Rockford’s Temperature Records
(Rockford Coop Station 1905 – 1950; Rockford Municipal Airport 1951 – present)
 
Rockford’s 100's
Daily high temperatures of 100 degrees or greater recorded in Rockford
(from earliest to most recent).
 
                             Date                                                                    Temperature                
                        August 5, 1896................................................................ 100
                        July 9, 1897...................................................................... 100
                        July 4, 1911...................................................................... 101
                        July 5, 1911...................................................................... 100
                        July 6, 1911...................................................................... 102
                        June 30, 1913................................................................... 100
                        July 31, 1913.................................................................... 101
                        September 3, 1913........................................................... 100
                        July 28, 1916.................................................................... 103
                        July 29, 1916.................................................................... 104
                        July 30, 1916.................................................................... 104
                        July 31, 1916.................................................................... 105
                        August 5, 1916................................................................ 102
                        August 19, 1916.............................................................. 100
                        August 21, 1916.............................................................. 100
                        July 31, 1917.................................................................... 101
                        August 1, 1917................................................................ 100
                        August 5, 1918................................................................ 104
                        August 6, 1918................................................................ 102
                        August 7, 1918................................................................ 101
                        July 4, 1921...................................................................... 100
                        July 7, 1921...................................................................... 100
                        July 11, 1921.................................................................... 104
                        July 12, 1921.................................................................... 103
                        July 13, 1921.................................................................... 104
                        September 6, 1922........................................................... 102
                        September 7, 1922........................................................... 100
                        September 8, 1922........................................................... 101
                        June 24, 1923................................................................... 100
                        September 4, 1925........................................................... 101
                        September 5, 1926........................................................... 100
                        July 19, 1930.................................................................... 100
                        July 20, 1930.................................................................... 102
                        July 27, 1930.................................................................... 100
                        August 3, 1930................................................................ 100
                        June 26, 1931................................................................... 100
                        June 28, 1931................................................................... 100
                        June 29, 1931................................................................... 103
                        June 30, 1931................................................................... 102
                        July 1, 1931...................................................................... 101
                        July 28, 1931.................................................................... 100
                        July 15, 1932.................................................................... 100
                        June 20, 1933................................................................... 100
                        June 27, 1933................................................................... 103
                        May 31, 1934................................................................... 106
                        June 1, 1934..................................................................... 106           
                        June 3, 1934..................................................................... 100
                        June 28, 1934................................................................... 103
                        July 20, 1934.................................................................... 101
                        July 21, 1934.................................................................... 102
                        July 22, 1934.................................................................... 104
                        July 23, 1934.................................................................... 104
                        July 24, 1934.................................................................... 107
                        July 25, 1934.................................................................... 105
                        August 9, 1934................................................................ 100
                        July 30, 1935.................................................................... 100
                    1*July 6, 1936...................................................................... 102
                    1*July 7, 1936...................................................................... 105
                    1*July 8, 1936...................................................................... 104
                    1*July 9, 1936...................................................................... 101
                    1*July 10, 1936.................................................................... 106
                    1*July 11, 1936.................................................................... 108
                    1*July 12, 1936.................................................................... 109
                    1*July 13, 1936.................................................................... 110
                    1*July 14, 1936.................................................................... 112
                     *July 16, 1936..................................................................... 100
                     *July 17, 1936..................................................................... 104
                     *July 26, 1936..................................................................... 103
                     *August 9, 1936................................................................. 100
                     *August 18, 1936............................................................... 101
                     *August 22, 1936............................................................... 101
                        August 16, 1937.............................................................. 102
                        September 7, 1939........................................................... 103
                        September 14, 1939......................................................... 101
                        September 15, 1939......................................................... 102
                        July 23, 1940.................................................................... 100
                        July 24, 1940.................................................................... 100
                        July 25, 1940.................................................................... 104
                        July 28, 1941.................................................................... 100
                        July 29, 1941.................................................................... 102
                        August 11, 1941.............................................................. 101
                        August 6, 1947................................................................ 100
                        August 18, 1947.............................................................. 100
                        August 19, 1947.............................................................. 100
                        August 20, 1947.............................................................. 100
                        August 23, 1947.............................................................. 101
                        August 24, 1947.............................................................. 102
                        August 24, 1948.............................................................. 100
                        August 31, 1953.............................................................. 101
                        September 1, 1953........................................................... 102
                        September 2, 1953........................................................... 101
                        July 26, 1955.................................................................... 102
                        July 27, 1955.................................................................... 103
                        August 21, 1955.............................................................. 100
                       2July 1, 1956..................................................................... 100
                       2June 20, 1988................................................................... 101
                        June 21, 1988................................................................... 100
                        June 25, 1988................................................................... 101
                        July 15, 1988.................................................................... 102
                        August 1, 1988................................................................ 101
                        August 16, 1988.............................................................. 104
                        August 17, 1988.............................................................. 102
                        July 10, 1989.................................................................... 100
 
1 Greatest number of consecutive 100 degree days (9)
*Greatest number of 100 degree days in one year (15)
                       2Marks a 33 year period in which temperatures did not climb to 100 degrees
 
                          Number of Days of 100 degrees or More by Decade
 
                        1893 – 1899..................................................................... 2
                        1900 – 1909..................................................................... 0
                        1910 – 1919..................................................................... 18
                        1920 – 1929..................................................................... 11
                        1930 – 1939..................................................................... 44
                        1940 – 1949..................................................................... 13
                        1950 – 1959..................................................................... 7
                        1960 – 1969..................................................................... 0
                        1970 – 1979..................................................................... 0
                        1980 – 1989..................................................................... 8
                        1990 – 1999..................................................................... 0
 
 
 
Greatest Consecutive Number of Days in Each Year with Maximum Temperature 90 Degrees or Higher
 
1895…6          1896…9          1897…8          1898…5          1899…M        1900…M       
1901…M        1902…M        1903…3          1904…M        1905…5          1906…3         
1907…1          1908…3          1909…2          1910…5          1911…6          1912…2         
1913…8          1914…6          1915…1          1916…21        1917…4          1918…4         
1919…6          1920…3          1921…21        1922…8          1923…7          1924…2         
1925…8          1926…4          1927…5          1928…3          1929…10        1930…5         
1931…9          1932…11        1933…8          1934…8          1935…11        1936…13       
1937…10        1938…4          1939…7          1940…8          1941…13        1942…5         
1943…7          1944…7          1945…4          1946…M        1947…13        1948…10       
1949…7          1950…3          1951…2          1952…3          1953…11        1954…3         
1955…10        1956…6          1957…3          1958…2          1959…8          1960…5         
1961…5          1962…3          1963…4          1964…3          1965…2          1966…4
1967…3          1968…5          1969…2          1970…4          1971…3          1972…3         
1973…4          1974…3          1975…5          1976…3          1977…4          1978…5         
1979…1          1980…2          1981…2          1982…1          1983…10        1984…2         
1985…2          1986…4          1987…10        1988…9          1989…9          1990…3         
1991…7          1992…2          1993…2          1994…5          1995…8          1996…4         
1997…2          1998…4          1999…5          2000…3          2001…6          2002…5         
2003…3          2004…1          2005…7          2006…3          2007…4
 
Greatest Consecutive Number of days with Maximum Temperature
90 degrees or Higher
 
21 days:                                                                       13 days:
            July 12 – August 1, 1916                                            July 6 – July 18, 1936
            June 28 – July 18, 1921                                              July 23 – August 4, 1941
                                                                                                August 2 – August 14, 1947
           
 
Greatest Number of days with Maximum Temperature 90 degrees or Higher in any Year
 
1………62 days (1921)                                              7………45 days (1933)
2………53 days (1895)                                              8………44 days (1931)
3………52 days (1934)                                              9………42 days (1916)
4………49 days (1936                                               10……..40 days (1941, 1947, and 1945)
5………46 days (1937 and 1988)                             
 
*(Normally there are 21 days where the maximum temperature reaches at least 90 degrees at Rockford, which is 4 more days than for O’Hare)
 
Greatest Number of days with Maximum Temperature 90 degrees or Higher by Month
 
April............ 2 days (1930)                                      August.............. 24 days (1947)
May............. 10 days (1934)                                    September......... 11 days (1895 and 1939)
June............. 20 days (1933)                                    October............. 4 days (1922)
July.............. 27 days (1921)
 
Least Number of days with Maximum Temperature 90 degrees or Higher in any Year
 
1 day (1915 and 2004)                                             4 days (1967 and 2000)
2 days (1979)                                                           5 days (1907, 1969, and 1996)
3 days (1951, 1981, and 1982)                      
                                   
 
Highest Temperatures Recorded in Rockford (102 degrees and higher)
 
112…….July 14, 1936                                              103…….July 28, 1916
                                                                                                 July 12, 1921
110…….July 13, 1936                                                            June 29, 1931
                                                                                                 June 27, 1933
109…….July 12, 1936                                                            June 28, 1934
                                                                                                 July 26, 1936
108…….July 11, 1936                                                            September 7, 1939
                                                                                                 July 27, 1955
107…….July 24, 1934                                                           
          102…….July 6, 1911
106…….May 31, 1934                                                           August 5, 1916
               June 1, 1934                                                             August 8, 1918
               July 10, 1936                                                            September 6, 1922
                                                                                                 July 20, 1930
105…….July 31, 1916                                                            June 30, 1931
               July 25, 1934                                                            July 21, 1934
               July 7, 1936                                                             July 6, 1936
                                                                                                 August 16, 1937
104…….July 29, 1916                                                            September 15, 1939
               July 30, 1916                                                            July 29, 1941
               August 5, 1918                                                        August 24, 1947
               July 11, 1921                                                            September 1, 1953
               July 13, 1921                                                            July 26, 1955
               July 22, 1934                                                            July 15, 1988
               July 23, 1934                                                            August 17, 1988
               July 8, 1936
               July 17, 1936
               July 25, 1940
               August 16, 1988
 
 
 
Highest Daily Mean Temperatures Recorded in Rockford
(88 degrees and higher)
 
  93……...July 14, 1936                                           88……..June 3, 1895
                                                                                                July 14, 1896
   92……...July 12, 1936                                                         July 9, 1897
                  July 13, 1936                                                         July 31, 1913
                                                                                                July 28, 1916
   91……...August 6, 1918                                                     August 7, 1916
                  July 24, 1934                                                         August 7, 1918
                  July 11, 1936                                                         August 3, 1930
                                                                                                August 4, 1930
   90……...July 30, 1916                                                         June 28, 1931
                  July 31, 1916                                                         June 30, 1931
                  July 22, 1934                                                         July 1, 1931
                  July 25, 1934                                                         July 15, 1932
                  July 10, 1936                                                         July 21, 1932
                  September 7, 1939                                                July 23, 1934
                  July 25, 1940                                                         August 22, 1936
                                                                                                July 28, 1941
   89……...August 8, 1896                                                     August 18, 1947
                  July 5, 1911                                                           August 24, 1947
                  July 29, 1916                                                         July 26, 1955
                  June 29, 1931                                                        July 23, 1965
                  July 29, 1941                                                         August 1, 1988
                  July 27, 1955                                                         August 15, 1988
                  August 16, 1988                                                   July 9, 1989
                  August 17, 1988                                                   July 21, 2002
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Greatest Consecutive Number of Days in Each Year with Minimum Temperature Zero Degrees or Lower
 
1895…1          1896…3          1897…6          1898…3          1899…M        1900…M       
1901…M        1902…M        1903…M        1904…M        1905…M        1906…1         
1907…5          1908…3          1909…6          1910…7          1911…5          1912…17       
1913…3          1914…5          1915…5          1916…5          1917…6          1918…8         
1919…4          1920…5          1921…1          1922…3          1923…3          1924…6         
1925…4          1926…3          1927…4          1928…1          1929…5          1930…3         
1931…1          1932…4          1933…6          1934…2          1935…4          1936…8         
1937…1          1938…2          1939…1          1940…4          1941…3          1942…9         
1943…3          1944…2          1945…5          1946…M        1947…M        1948…4         
1949…2          1950…5          1951…7          1952…3          1953…3          1954…2         
1955…5          1956…3          1957…7          1958…8          1959…4          1960…3         
1961…5          1962…6          1963…13        1964…2          1965…9          1966…6
1967…4          1968…6          1969…4          1970…8          1971…4          1972…7         
1973…2          1974…4          1975…5          1976…4          1977…8          1978…11       
1979…11        1980…4          1981…4          1982…12        1983…5          1984…8         
1985…6          1986…5          1987…4          1988…7          1989…7          1990…5         
1991…3          1992…2          1993…3          1994…9          1995…4          1996…8         
1997…5          1998…1          1999…4          2000…12        2001…2          2002…2         
2003…2          2004…4          2005…4          2006…2          2007…8
 
 
Greatest Consecutive Number of days with Minimum Temperature
Zero or Lower
 
17 days:                                                                       13 days:                                              
            January 1-January 17, 1912                                        January 19 – January 31, 1963                       
 
Greatest Number of days with Minimum Temperature Zero degrees or Lower in any Year
 
1………45 days (1963)                                              7………31 days (1936)
2………38 days (1977)                                              8………30 days (1929)
3………37 days (1978)                                              9………28 days (1976)
4………35 days (1979 and 1985)                              10……..27 days (1917, 1924, and 1951)
6………34 days (1912)                                 
 
*(Normally there are 15 days where the minimum temperature falls to 0 degrees or below at Rockford, which is 2 more days than for O’Hare)
 
 
 
 
Greatest Number of days with Minimum Temperature of Zero or Lower by Month
 
November... 3 days (1929, 1976, and 1977)           February............ 18 days (1936)
December.... 15 days (1963)                                    March................ 5 days (1943)
January........ 21 days (1977)
 
Least Number of days with Minimum Temperature Zero degrees or Lower in any Year
 
1 day (1931 and 1939)                                             5 days (1908, 1937, 1952, 1954, 1956,
2 days (1895 and 2002                                                         1964, 1987, and 1992)
3 days (1898, 1906, 1921, 1998)                             6 days (1907 and 1928)
                                   
 
Lowest Temperatures Recorded in Rockford (-21 degrees and lower)
 
-27………..January 10, 1982                                     -22 (cont)……            January 21, 1970
                                                                                                            February 2, 1976
-26……. …January 20, 1985                                                              January 16, 1977
                                                                                                            January 21, 1984
-25……….January 5, 1924                                                                 February 1, 1985
                  February 9, 1933                                                               December 25, 2000
                  January 17, 1982
                                                                                    -21………….. February 1, 1918
-24………January 23, 1936                                                                January 4, 1919
                  January 11, 1979                                                               January 21, 1924
                  January 15, 1979                                                               December 28, 1924
                  January 16, 1982                                                               January 22, 1936
                  December 24, 1983                                                           January 12, 1974
                  January 19, 1985                                                               January 16, 1979
                  January 19, 1994                                                               February 5, 1979
                  February 3, 1996                                                               January 9, 1982
                                                                                                            December 19, 1983
-23………January 25, 1897                                                                December 23, 1983
                  December 26, 1914                                                           January 10, 1988
                  January 18, 1994                                                               January 15, 1994
                                                                                                            January 16, 1994
-22………January 28, 1915                                                                February 2, 1996
                  February 20, 1929                                                             January 5, 1999
                  January 18, 1930
                  January 23, 1963  
 
 
 
 
 
 
Lowest Daily Mean Temperatures Recorded in Rockford
(-11 degrees and lower)
 
-19………..January 18, 1994                                     -14 (cont)……            January 15, 1972
                                               
-18….…….January 5, 1924                                        -13……...…....January 7, 1942
                   December 24, 1983                                                          January 6, 1988
                   February 3, 1996                                                             
                                                                                    -12………….. January 21, 1970        
-17………. January 25, 1987                                                              January 2, 1979
                   January 15, 1994                                                              January 17, 1982
                   February 2, 1996                                                              December 19, 1983
                                                                                                            January 20, 1984
-16………. January 6, 1912                                                                December 21, 1989
                   February 9, 1933                                     
                   January 23, 1963                                      -11………….. January 16, 1897        
                   January 10, 1982                                                              February 2, 1917
                   December 23, 1983                                                          December 28, 1924
                   January 20, 1985                                                              January 18, 1930
                                                                                                            January 18, 1940
-15………. January 24, 1897                                                              January 30, 1951
                   January 7, 1912                                                                February 5, 1979
                   January 23, 1936                                                              January 15, 1979
                   January 29, 1966                                                              December 22, 1989
                   January 16, 1977                                                              January 31, 1996
                                                                                                            February 4, 1996        
-14………. January 12, 1912
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
Longest Continuous Period Below Freezing
 
46 Days………January 9, 1978 – February 23, 1978
 
43 Days………December 28, 1976 – February 8, 1977
 
38 Days………January 16, 1936 – February 22, 1936
 
33 Days………January 15, 1985 – February 16, 1985
 
30 Days………January 1, 1893 – January 30, 1983
                         January 21, 1979 – February 19, 1979
 
 
Longest Consecutive Number of Hours Below Zero
 
120** hours…...January 31, 1996 – February 4, 1996
 
**NOTE: The LCD only reports observed temperatures in three hour increments. Whereas below zero degree conditions were recorded between 12:00 AM LST on January 31 – 12:00 AM LST on February 5, upwards of 4 additional hours (2 hours on each side of the time window) are possible for the extreme cold wave, yielding a possible 120 - 124 hours of below zero conditions from 10:00 PM LST January 30, 1996 – 2:00 AM LST February 5, 1996.
 
 
First Freeze of the Season
 
Average Date:             October 7th
Earliest Date:              September 13, 1975 (32)
Latest Date:                November 4, 1973 (31)
 
Last Spring Freeze of the Season
 
Average Date:             May 1st
Earliest Date:              March 31, 1946 (32)
Latest Date:                May 27, 1992 (30)
 
First Killing Frost (28 Degrees or Lower)
 
Average Date:             October 19th
Earliest Date:              September 24, 1976 (28)
Latest Date:                November 10, 1994 (28)
 
 
 
 
 
 
 
Largest Temperature Change from One Day to the Next
High and Low temperatures for the days in parentheses
 
Drop of 65 Degrees:   January 5 – 6, 1909                 (54/23); (23/-11)
 
Rise of 63 Degrees:     April 9 – 10, 1930                   (73/30); (93/50)
 
Drop of 62 Degrees:   November 11 – 12, 1911        (74/50); (50/12)
 
Rise of 59 Degrees:     February 22 – 23, 1936           (25/-17); (42/22)
                                    March 17 – 18, 1976**           (37/11); (70/31)
 
Rise of 58 Degrees:     January 29 – 30, 1926             (38/-6); (52/37)
 
Drop of 57 Degrees:   February 1 – 2, 1976**           (35/-9); (7/-22)
                                    January 18 – 19, 1996             (57/7); (7/0)
 
Rise of 57 Degrees:     January 21 – 22, 1924             (2/21); (36/-7)
                                    March 31 – April 1, 2003        (56/24); (81/45)
 
**Note: Interestingly enough, the first few months of 1976 saw one of the largest rises and drops and temperature from one day to the next.
 
Biggest Range in a Single Calendar Day
High and Low temperature in parentheses
 
53 Degrees:                 February 12, 1999                   (66/13)
 
52 Degrees:                 March 23, 1939                       (82/30)
 
50 Degrees:                 April 2, 1981                           (79/29)
                                    January 18, 1996                     (57/7)
 
Greatest One Hour Drop in Temperature
 
Missing for now
 
 
Other Significant Temperature Changes
 
Missing for now
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