Climatological Report (Monthly)
Issued by NWS Detroit/Pontiac, MI

Home | Current Version | Previous Version | Text Only | Print | Product List | Glossary On
Versions: 1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22
000
CXUS53 KDTX 032052
CLMDTW

CLIMATE REPORT
NATIONAL WEATHER SERVICE DETROIT/PONTIAC MI
400 PM EDT MON AUG 3 2009

...................................

...THE DETROIT MI CLIMATE SUMMARY FOR THE MONTH OF JULY 2009...

CLIMATE NORMAL PERIOD 1971 TO 2000
CLIMATE RECORD PERIOD 1870 TO 2009

WEATHER         OBSERVED          NORMAL  DEPART
                 VALUE   DATE(S)  VALUE   FROM
                                          NORMAL
................................................
TEMPERATURE (F)
RECORD
 HIGH             105   07/24/1934
 LOW               42   07/06/1972
HIGHEST            86   07/11        MM      MM
LOWEST             52   07/13        MM      MM
AVG. MAXIMUM     78.4              83.4    -5.0
AVG. MINIMUM     59.4              63.6    -4.2
MEAN             68.9              73.5    -4.6
DAYS MAX >= 90      0               5.0    -5.0
DAYS MAX <= 32      0               0.0     0.0
DAYS MIN <= 32      0               0.0     0.0
DAYS MIN <= 0       0               0.0     0.0

PRECIPITATION (INCHES)
RECORD
 MAXIMUM         8.76   1878
 MINIMUM         0.50   1930
TOTALS           2.56              3.16   -0.60
DAILY AVG.       0.08              0.10   -0.02
DAYS >= .01        11                MM      MM
DAYS >= .10         6                MM      MM
DAYS >= .50         1                MM      MM
DAYS >= 1.00        1                MM      MM
GREATEST
 24 HR. TOTAL    1.04   07/11 TO 07/11
                        07/10 TO 07/11
                        07/11 TO 07/11
 STORM TOTAL       MM
 (MM/DD(HH))            MM

SNOWFALL (INCHES)
RECORDS
 TOTAL            0.0   0
                        0
                        0
TOTALS            0.0               0.0     0.0
 LIQUID EQUIV    0.00              0.00    0.00
SINCE 7/1         0.0               0.0     0.0
 LIQUID 7/1      0.00
DAYS >= TRACE       0               0.0     0.0
DAYS >= 1.0         0               0.0     0.0
GREATEST
 SNOW DEPTH         0   MM
 24 HR TOTAL      0.0   07/31 TO 07/31
 STORM TOTAL       MM
 (MM/DD(HH))            MM

DEGREE_DAYS
HEATING TOTAL       5                 0       5
 SINCE 7/1          5                 0       5
COOLING TOTAL     131               254    -123
 SINCE 1/1        291               447    -156

FREEZE DATES
RECORD
 EARLIEST     MM
 LATEST       MM
EARLIEST                        MM
LATEST                          MM
.................................................

WIND (MPH)
AVERAGE WIND SPEED              7.1
HIGHEST WIND SPEED/DIRECTION    28/190    DATE  07/15
HIGHEST GUST SPEED/DIRECTION    37/190    DATE  07/15

SKY COVER
POSSIBLE SUNSHINE (PERCENT)   MM

NUMBER OF DAYS FAIR            2
NUMBER OF DAYS PC             18
NUMBER OF DAYS CLOUDY         11

AVERAGE RH (PERCENT)     68

WEATHER CONDITIONS. NUMBER OF DAYS WITH
THUNDERSTORM              3     MIXED PRECIP               0
HEAVY RAIN                3     RAIN                       7
LIGHT RAIN               10     FREEZING RAIN              0
LT FREEZING RAIN          0     HAIL                       0
HEAVY SNOW                0     SNOW                       0
LIGHT SNOW                0     SLEET                      0
FOG                      19     FOG W/VIS <= 1/4 MILE      0
HAZE                     11

-  INDICATES NEGATIVE NUMBERS.
R  INDICATES RECORD WAS SET OR TIED.
MM INDICATES DATA IS MISSING.
T  INDICATES TRACE AMOUNT.


$$
---------------------------------------------------------------

CLIMATOLOGICAL STATISTICS FOR THE NWS WHITE LAKE - JULY 2009

...TEMPERATURE DATA...               ...PRECIPITATION DATA...

AVERAGE MAXIMUM.... 76.0             MONTHLY TOTAL ........... 1.37
AVERAGE MINIMUM.... 54.1             GREATEST IN 24HRS........ 0.50
MONTHLY AVERAGE.... 65.0             ON THE 19TH
                                     2009 TOTAL...............22.17

...HEATING DEGREE DAYS...            ...SNOWFALL DATA...
MONTHLY TOTAL......... 55            MONTHLY TOTAL..........   0.0
2008-09 SEASON TOTAL.. 55            2009-10 SEASON TOTAL...   0.0

...COOLING DEGREE DAYS...
MONTHLY TOTAL.......... 55
2009 TOTAL.............150

==================================================================

           CLIMATOLOGICAL SUMMARY FOR DETROIT - JULY 2009

...UP NORTH WEATHER MAKES A TRIP SOUTH THIS JULY WITH THIRD COLDEST
   JULY ON RECORD FOR METRO DETROIT...
...SEVERE WEATHER NEARLY NON-EXISTENT FOR AN USUALLY ACTIVE MONTH...
...SOME AREAS BEGIN TO DRY OUT DURING THE MONTH...
***DOMINANT TEMPERATURE/RAIN TREND...BELOW NORMAL/BELOW NORMAL***

WHAT A JULY IT WAS THIS SUMMER AS THE "UP NORTH" WEATHER VACATIONED
DOWN HERE IN THE SOUTH! IT WAS ABNORMALLY COOL BUT DELIGHTFUL FOR MOST
ACROSS SOUTHEAST LOWER MICHIGAN (THOUGH HOT WEATHER INTERESTS MAY
DISAGREE). NORMALLY IN JULY...WE SEE ABOUT HALF OUR 90S /5-6/ FOR THE
SUMMER /12/ AND THIS JULY WE COULDN`T EVEN MUSTER AN 87! ONLY FOUR
TIMES IN DETROIT`S CLIMATE RECORD HISTORY HAVE WE FAILED TO REACH 87 IN
JULY AND THAT WAS IN 1875...1907...1992 AND NOW 2009. WITH AN AVERAGE
HIGH OF 78.4 AND A LOW OF 59.4...OUR JULY AVERAGE OF 68.9 WAS MORE LIKE
THE TIP OF NORTHERN LOWER MICHIGAN THAN THE METRO DETROIT AREA. THAT
AVERAGE 68.9 DEGREES THIS JULY JUST BARELY MISSED SECOND PLACE OF 68.8
SET IN THE COLD SUMMER OF 1992. THE AVERAGE LOW FOR JULY OF 1992 /60.5/
WAS IN FACT A DEGREE WARMER THAN THIS PAST JULY /59.4/ AND THIS IN
SPITE OF SOME INCREASE IN THE HEAT ISLAND (WHICH SHOWS UP MANY AT
NIGHT). TAKING THIS FURTHER...THE TEMPERATURE FELL BELOW 60 DEGREES IN
18 DAYS OUT OF THE 31 IN JULY (THE RECORD IS 20 DAYS SET BACK IN THE
COLDEST JULY ON RECORD 1891).


LOOKING BACK OVER THE DECADES AT DETROIT...THERE HAVE BEEN 14 JULYS
(INCLUDING THIS JULY) THAT CONTAINED NO 90S (OR ABOUT ONCE A DECADE).
WHAT IS THE MOST NOTEWORTHY...HOWEVER...IS WHEN THE NO 90S IN JULY
OCCURRED (GIVE OR TAKE 25 YEARS)...RIGHT AROUND THE TURN OF THE CENTURY
IN 1900 AND AGAIN RECENTLY AROUND 2000. CHECK OUT THE YEARS THAT NO 90S
WERE REGISTERED IN JULY AND A PATTERN EVOLVES.../1875/1882/1884/1891/
/1907/1912/1915/1922/.../1943.../1979/1992/2000/2008/2009. SO...WITH
THE EXCEPTION OF 1943...ALL THE NONE 90 JULYS OCCURRED WITHIN 25 YEARS
OF THE CENTURY MARKS AND WE SEEM TO BE IN THAT PATTERN AGAIN...ONLY
TIME WILL TELL.

ALL BUT ONE DAY AVERAGED BELOW NORMAL IN JULY (AND ONE WAS NORMAL) IN
THE ENTIRE MONTH. IN ADDITION...THERE WERE TWO NOTABLE COOL PERIODS
DURING THE MONTH. FIRST OFF...THE 1ST THROUGH THE 9TH BROUGHT NINE
CONSECUTIVE DAYS AVERAGING 7 DEGREES BELOW NORMAL. THE COOLEST WAS ON
THE SECOND WHEN THE MERCURY FAILED TO EVEN GET ABOVE 70 /68/. THEN...
THE NEXT STRETCH CAME MID MONTH FROM THE 17TH THROUGH THE 24TH WHEN
TEMPERATURES AVERAGED 6.3 BELOW NORMAL. THE LARGEST BELOW NORMAL
DEPARTURE FOR THE MONTH CAME ON THE 18TH WHEN AN AVERAGE OF 63 CAME IN
11 DEGREES BELOW NORMAL. TAKE A LOOK AT THE COOLING DEGREE DAYS VERSUS
HEATING DEGREE DAYS FOR THE NWS IN WHITE LAKE...THEY ARE THE SAME
/55/...HIGHLY UNUSUAL FOR JULY.

AFTER SEVERAL DOMINANT WET MONTHS...JULY BEGAN SHOWING SIGNS OF "DRYING
TREND". THE DRIER WEATHER DEVELOPED IN POCKETS ACROSS SOUTHEAST LOWER
MICHIGAN BUT WHETHER ITS A TREND OR JUST SHORT-LIVED REMAINS TO BE
SEEN. THERE ALSO WAS LITTLE IN THE WAY OF SEVERE WEATHER WITH JUST AN
ISOLATED CASE OR TWO...NOT TYPICAL FOR JULY.

DEEDLER










  • National Weather Service
  • Detroit/Pontiac, MI Weather Forecast Office
  • 9200 White Lake Road
  • White Lake, MI 48386
  • 248-620-9804
  • Page Author: DTX Webmaster
  • Web Master's E-mail: w-dtx.webmaster@noaa.gov
  • Page last modified: Nov 10th, 2009 17:45 UTC
USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.