2011 Climate Summary for Casper

Natrona County International Airport

Month

Avg

High

Avg

Low

Average

Temp

Departure

From

Normal

Total

Pcpn

Departure

From

Normal

Snowfall

Avg Snow

Departure

Maximum Wind Gust (MPH)

January

32.3

14.5

23.4

1.3

0.44

-0.07

12.9

9.1

3.8

45

February

31.0

10.3

20.6

-6.1

0.86

0.29

12.6

9.8

2.8

55

March

49.2

24.9

37.1

1.9

0.46

-0.36

7.0

10.9

-3.9

62

April

54.3

28.4

41.3

-1.4

1.37

0.08

5.4

11.6

-6.2

54

May

59.7

35.4

47.6

-4.6

3.37

1.35

0.7

2.9

-2.2

56

June

78.0

43.0

60.5

-1.7

1.55

-0.06

0

0.1

-0.1

55

July

90.5

55.6

73.1

2.6

1.52

0.11

0

0

0.0

58

August

90.2

53.2

71.7

2.7

0.23

-0.62

0

0

0.0

60

September

78.1

41.8

59.9

2.0

0.10

-0.98

0

1.8

-1.8

47

October

62.2

34.9

48.5

3.3

1.44

0.33

1.0

7.4

-6.4

52

November

44.0

21.2

32.6

-0.6

1.24

0.48

14.3

10.3

-4.0

59

December

 33.1  14.9

 24.0

0.2
0.71

0.10

11.4

11.0

0.4

53

2011 Annual

58.5

31.5

45.0

-0.4
13.29
0.65

65.3

74.9

-9.6

62

1981-2010 Normals Period of Record 1939-2011                       

 

Yearly Extremes:
 
Temperatures: 

Highest Temperature: 98 degrees on July 3rd and 25th.
Days with Maximum Temperature 90 deg F or Higher: 39
Days with Maximum Temperature 32 deg F or Lower:  45
 
Lowest Temperature: -24 degree on January 10th.
Days with Minimum Temperature 32 deg F or Lower: 186
Days with Minimum Temperature 0 deg F or Lower:  16
 
Precipitation:

Highest Daily Precipitation: 0.75 on October 6th.
Days with Precipitation 0.01 Inches or More: 91
Days with Precipitation 0.10 Inches or More: 39
Days with Precipitation 0.50 Inches or More:  7
Days with Precipitation 1.00 Inches or More:  0*
 
Highest Daily Snowfall: 7.5 inches on January 9th*
Days with Snowfall: 49
Days with Snowfall of 1 Inch or More: 18

Wind:

 Highest Wind Gust: 62 mph on March 19th.

 
Records set during 2011:
 
Temperatures (degrees F):


Max


April: 75 on the 2nd.
July: 98 on the 3rd (tie) and 25th.
August: 96 on the 27th (tie).
September: 88 on the 25th.

Min:  

April: 15 on the 23rd.
November: -14 on the 19th, -14 on the 20th (tie).

 

 Average:

Monthly:      7th coldest February. 
                          
4th coldest May.
           

Annual:      None.

 

Precipitation:

One day Precipitation:

February:  0.42 on the 20th.
May:  0.60 on the 9th.
November:  0.50  on the 1st.
December:  0.38  on the 31st.

 

    
One day Snowfall (inches):

January:  7.5  on the 9th.
February:  6.0  on the 20th.
November:  4.6  on the 1st, 6.7 on the 18th.
December:  3.8 on the 21st.

Monthly Precipitation:

2rd driest September (tie), 9th wettest November.


Annual Precipitation:  None set.
 

Monthly Snowfall:   None set.
                            
 

Seasonal Snowfall: None set.

Yearly: None set.

 
 

Monthly Reviews:
 

 JANUARY 2011 –  Slightly Drier and Warmer Than Normal

     The average temperature for Casper in January was 23.4 degrees which is 6.1 degrees below normal.  The highest reading was 49 degrees which occurred on the 28th. The lowest reading was 24 below zero which occurred on the 10th.  No record highs or lows were set in January. 

     Total precipitation for the month was 0.44 inches which was 86 percent of normal.
Casper received 12.9 inches of snowfall for the month which is was 142 percent of normal. The highest daily snowfall
total for the month was 7.5 inches on the 9th which also set a daily snowfall record for the date. 

     The highest wind gust was 45 mph out of the southwest on the 20th.

Storm Total Snowfall
January 8-9, 2011

  Storm Total Snowfall
January 18-19, 2011

Station Name Snowfall (inches)   Station Name Snowfall (inches)
Casper Airport 7.7   Casper 4-6
Mills 7.5   2 S Casper 3.8
2 S Casper 6   Casper Mountain 3.5
Casper Mountain 4   3 NNE Casper 2.5
5 WSW Casper 3.3   10 WSW Casper 2
Grave Springs Snotel 3   Powder River 2
11 WSW Casper 3   4 NW Mills (near airport) 1.8
         

 

FEBRUARY 2011 - 7th Coolest on Record, Wetter Than Normal

     The average temperature for Casper in February was 20.6 degrees which is 6.1 degrees below 
normal, making it the 7th coolest February on record. The highest reading was 53 degrees which
occurred on the 15th and 16th. The lowest reading was 20 below zero which occurred on the 1st.
No record highs or lows were set in February. 
     Total precipitation for the month was 0.86 inches which is 134 percent of normal. Casper 
received 12.6 inches of snowfall for the month which is 129 percent of normal. 0.42 inches of
precipitation in the form of 6.0 inches on the 20th set daily precipitation and snowfall records,
respectively, for the date.
     The highest wind gust was 55 mph out of the southwest on the 28th.            
Coldest Februarys on Record
Rank Average Temperature (F)
Year(s)
1 11.9 1989
2 19.0 1960
3 19.6 1993
4 19.7 1942, 1985
6 20.2 1955
7 20.6 2011
8 20.8 1949, 1975
10 20.9 1964

 

MARCH 2011 –  14h Driest on Record, Above Normal Temperatures

     The average temperature for Casper in March was 37.1 degrees which is 1.9 degrees above
normal. The highest reading was 68 degrees which occurred on the 31st. The lowest reading
was 12 degrees which occurred on the 7th. No daily temperature records were set in March.
     Total precipitation for the month was 0.46 inches which is 56 percent normal.
Casper received 7.0 inches of snowfall for the month which is 64 percent of normal. 6.1 inches
of that total fell between the 3rd and 8th.
     The highest wind gust was 62 mph out of the southwest on the 19th. This was also the highest
wind gust of 2011.

 

 APRIL 2011 – Colder and Slightly Wetter than Normal

     The average temperature for Casper in April was 41.3 degrees which is 1.4 degrees below 
normal. The highest reading was 75 degrees which occurred on the 2nd, and also set a new record
high for the date.
The lowest reading was 15 degrees on the 23rd, setting a record
low for the date.
     Total precipitation for the month of April was 1.37 inches which is 106 percent of normal.
Casper received 5.4 inches of snowfall for the month which is 47 percent of normal.
     The highest wind gust was 54 mph out of the west on the 2nd.
 

MAY 2011 – 4th Coldest May,  12th Wettest May on Record

     The average temperature for Casper in May was 47.6 degrees which is 4.6 degrees below 
normal, and makes May 2011 the fourth
coldest May on record. The highest reading was 80 degrees
which occurred on the 8th. The lowest reading was 23 degrees which occurred on the 2nd.
No daily temperature records were set in May.
     Total precipitation for May is 3.37 inches which is 169 percent of normal. The highest daily 
precipitation total during the month was 0.60 inches on the 9th, which also set a daily precipitation
record for the date.
Casper received 0.7 inches of snowfall on the 19th which was also the total for
the month; 24 percent of normal.
     The highest wind was 56 mph out of the southwest on the 30th.          
Wettest Mays on Record
Rank Precipitation (inches)
Year(s)
1 6.46 1978
2 6.31 1995
3 5.59 1971
4 4.75 1991
5 4.26 2008
6 3.93 1952
7 3.88 1975
8 3.85 1957
9 3.80 1962
10 3.73 1946
11
 3.51  1981
12
 3.37  2011
13 3.35 1968
14 3.32 2000
15 2.97 1947
16 2.86 2007
Coldest Mays on Record
Rank Average Temperature (F) Year(s)
1 46.2
1950
2 46.5
2010
3 47.2
1946
4 47.6
2011
5 48.1
1968
 
 

JUNE 2011 – Cooler, Near Normal Precipitation

     The average temperature for Casper in June was 60.5 degrees, which is 1.7 degrees 
below the
normal. The highest reading was 94 degrees which occurred on the 29th.
The lowest reading was 31 degrees which occurred on the 4th.
No daily temperature records were
set in June.

     Total precipitation for the month was 1.55 inches which was 96 percent of normal.

     The highest wind gust was 55 mph out of the southwest on the 7th.

 

JULY 2011  – 14th Warmest on Record,  Slightly Wetter than Normal

     The average temperature for Casper in July was 73.1 degrees which is 2.6 degrees above normal.
The highest reading was 98 degrees which occurred on the 3rd and 25th; also setting new record highs
for the two dates. The lowest reading was 47 degrees which occurred on the 23rd.
Casper had 20
days in July with highs of 90 degrees or higher.
    Total precipitation for the month was 1.52 inches which was 108 percent of normal. 0.59 inches
of this total fell on the 26th, the highest daily total for the month.
     The highest wind gust was 58 mph out of the southwest on the 13th.
 

AUGUST 2011  – 14th Warmest, 16th Driest on Record

     The average temperature for Casper in August was 71.7 degrees which is 2.7 degrees above
normal. The highest temperature for the month was 96 degrees on the 25th and the 27th. The 96 degree
reading on the 27th tied a record high for the date. The lowest temperature for the month was 45
degrees on the 9th.

     Total precipitation for the month was 0.23 inches which was only 27 percent of normal, and the 16th driest August on record.

     The highest recorded wind gust for the month was 60 mph out of the southwest on the 26th.
 

 

SEPTEMBER 2011  – Second Driest on Record (tie),  Warmer than Normal

     The average temperature in September was 59.9 degrees which is 2.0 degrees above normal. The highest temperature for the month was 88 degrees on the 25th, which was also a new record high for the date. The lowest temperature for the month was 25 degrees on the 21st. 

     Total precipitation for the month was 0.10 inches, only 9 percent of normal and the second driest
September on record (tied with 1980). 0.09 of this total fell on the 21st.
     The highest recorded wind gust for the month was 47 mph out of the southwest on the 2nd.    
Driest Septembers on Record
Rank Precipitation Year(s)
1 0.07 1956
2 0.10 2011, 1980
4 0.11 1975
5 0.16 1969
6 0.18 1979
7 0.20 1983
8 0.21 1970, 1953
10 0.23 2005, 1981, 1954


 
 

OCTOBER 2011 – 12th Wettest on Record, Warm than Normal

     The average temperature for Casper in October was 48.5 degrees which is 3.3 degrees
above the normal. The highest temperature for the month was 86 degrees on the 1st.
The lowest temperature for the month was 17 degrees on the 28th. No daily temperature records were
set during the month.
     Total precipitation for the month was 1.44 inches which is 130 percent of normal.  0.75 of this 
total fell on the 6th. One inch of snow was recorded during the month, all on the 25th.
The monthly total is only 14 percent of normal.
     The highest recorded wind gust for the month was 52 mph out of the southwest on the 7th.
 

NOVEMBER 2011 –  9th Wettest on Record, Slightly Cooler than Normal

     The average temperature for Casper in November was 32.6 degrees which was 0.6 degrees below normal.  The highest temperature for the month was 59 degrees on the 4tht  The lowest temperature for the month was 14 degrees below zero on the 19th and 20th. This temperature set a new record low on the 19th and tied the record low on the 20th.  No record highs were set during the month.  

     Total precipitation for the month of November was 1,24 inches which was 163 percent of normal. During the month 14.3 inches of snow fell which was 139 percent of normal. The wettest and snowiest day of the month was on the 18th when 6.7 inches of snow fell equating to 0.51 inches of water; the snowfall total set a new daily snowfall record for the date.  0.50 inches of precipitation and 4.6 inches of snow on the 1st set daily precipitation and snowfall records, respectively, for the date.

     The highest recorded wind gust for the month was 59 mph out of the southwest on the 12th.


Wettest Novembers on Record
Rank Precipitation Year(s)
1 2.72 1983
2 1.83 1942
3 1.79 1994
4 1.56 1985
5 1.51 1947
6 1.48 1986
7 1.30 1956
8
1.27 1990
9 1.24 2011
10 1.19 1955

 

DECEMBER 2011 – Near Normal Temperatures, Wetter than Normal

     The average temperature for Casper in December was 24.0 degrees which was 0.2 degrees above 
normal. There were no record high or low temperatures set in December. The warmest reading for
the month was 50 degrees on the 30th. The lowest reading was 7 below zero on the 5
th.
     Total precipitation for December was 0.71 inches which was 116 percent of normal. The greatest one 
day precipitation was 0.38 on the 31st which also set a daily precipitation record for this date. During the
month 11.4 inches of snow fell which was 104 percent of normal.
 

 

 

 
 
 
 
 
 
 


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