2009 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

January

35.9

15.6

25.8

3.5

1.08

0.50

16.4

11.1

5.3

February

42.2

20.9

31.6

4.9

0.28

-0.36

4.1

10.7

-6.6

March

47.7

18.6

33.2

-1.8

1.00

0.10

17.5

12.3

5.2

April

52.1

27.8

40.0

-2.7

2.05

0.53

16.5

13.8

2.7

May

69.1

36.7

52.9

0.8

0.43

-1.95

T

4.9

-4.9

June

73.6

45.4

59.5

-3.2

2.23

0.80

0

0.1

-0.1

July

83.9

49.5

66.7

-3.3

3.45

2.16

0

0

0.0

August

84.2

46.6

65.4

-3.2

1.34

0.61

0

0

0.0

September

78.3

40.3

59.3

1.7

1.62

0.64

1.3

2.0

-0.7

October

48.2

25.8

37.0

-8.7

1.27

0.13

13.8

7.1

6.7

November

52.2

24.6

38.4

6.4

0.05

-0.77

0.6

12.0

-11.4

December

26.4

4.9

19.5

-8.2

0.97

0.35

19.5

11.9

7.6

Total/Ave

57.8

29.7

43.8

-1.1

15.77

2.74

89.7

85.9

3.8

     

 

  

Yearly Extremes:
 
Temperatures: 

Highest Temperature: 97 degrees on August 22nd.
Days with Maximum Temperature 90 deg F or Higher: 23
Days with Maximum Temperature 32 deg F or Lower: 48
 
Lowest Temperature: -29 degree on December 8th.
Days with Minimum Temperature 32 deg F or Lower: 204
Days with Minimum Temperature 0 deg F or Lower:    22
 
Precipitation:

Most Precipitation in 24 Hours: 1.61 on July 3rd.
Days with Precipitation 0.01 Inches or More: 100
Days with Precipitation 0.10 Inches or More: 45
Days with Precipitation 0.50 Inches or More:  6
Days with Precipitation 1.00 Inches or More:  1
 
Most Snowfall in 24 Hours: 10.6 inches on March 23rd.
Days with Snowfall: 49
Days with Snowfall of 1 Inch or More: 27

Wind:

 Highest Wind Gust: 68 mph on September 20th.

 
 
Records set during 2009:
 
Temperatures (degrees F):


Max

 

January: 57 on the 19th.
March:
64 on the 2nd, 72 on the 21st.

May: 88 on the 18th, 89 on the 19th.
August: 97 on the 22nd.
September:  86 on the 29th.
November:  71 on the 5th. 
         

Min:

          March:  -6 on the 27th.
          May:
25 on the 16th.
         
August: 38 on the 16th, 36 on the 17th (tie), 37 on the 18th.
          October: 22 on the 3rd, 12 on the 9th, 11 on the 10th, 16 on the 11th.

         
December:  -29 on the 8th, -15 on the 25th.

 

 Average:

Monthly:       4th Coldest July
                            Coldest August
                           
Coldest October

                  Coldest December

          Annual:     6th coldest year on record (43.8 average temperature, coldest year 1985 with
                         average temperature of 42.5
).

 

Precipitation:

One day Precipitation:

 

          January: 0.31 on the 24th.
          March: 0.88 on the 23rd.
          June: 0.40 on the 18th.
          July: 0.65 on the 1st.

   
One day Snowfall (inches):


           March: 10.6 on the 23rd.
           December: 6.3 on the 26th.

 

 

Monthly Precipitation: 5th wettest January.
                                 3rd driest May.

                                 2nd wettest July.
                                
2nd driest November.

                                 5th wettest December.


Annual Precipitation:  9th wettest year on record (15.77 inches of precipitation, wettest year
                                     was in 1982 with 20.48 inches of precipitation).

 

Monthly Snowfall: 7th snowiest October.
                               4th least snowiest November.
                              
4th snowiest December.
 

Seasonal Snowfall: None set

Yearly: None Set

 

 

Monthly Reviews:
 

JANUARY 2009 –  Fifth Wettest on Record-Warmer than Normal

3 to 6 inches of snowfall ushered in 2009 in the Casper area.
A storm system on the 11th-12th produced 2 to 4 inches of snow in the Casper area
.
An Arctic cold front plunged through the area on the 26th with the Natrona County Airport dropping to -21.
 

     The average temperature for Casper was 25.8 degrees which was 3.5 degrees above normal. 
The highest temperature was 57 degrees which occurred on the 19th, a new record high for the date.
The lowest temperature was -21 degrees which occurred on the 26th.
          

      Total precipitation for the month was 1.08 inches which was 186 percent of normal. The greatest daily precipitation was 0.31 inches which occurred on both the 3rd and 24th. The greatest daily snowfall of 4.4 inches fell on the 3rd.

     The peak wind gust was 56 mph out of the southwest on the 2nd.

 

February 2009 - Warm and Dry

     The average temperature for Casper was 31.6 degrees which was 4.9 degrees above normal...or the 12th warmest February on record since 1939.  Only two days in February, the 1st and 11th, had highs of 32 degrees or below.  No low temperatures below zero were recorded during the month. The highest temperature was 58 degrees which occurred on the 24th.  The lowest temperature was 1 degree which occurred on the 20th. No record highs or lows were set this month.

      Total precipitation for the month was 0.28 inches which was only 44 percent of normal. The greatest daily snowfall was 3.2 inches that fell on the 9th.

     The peak wind gust was 49 mph out of the southwest on the 25th.
 
MARCH 2009 –  Springtime in the Rockies, Lions and Lambs Battle It Out
     March began with a record high temperature of 64 set on the 2nd.  An Arctic airmass plunged down on the 9th with
the low temperature plunging to 9 below zero on the 10th.  A record high of 72 degrees was set on the 21st, shattering
the old record of 67 set in 1995.  This Spring weatherwas followed shortly by a dumping of 10.6 inches of snow at the
     Casper airport on the 23rd.  Another storm dumped an additional 4 to 9 inches of snow on the 26th, followed by a record
low temperature of 6 below zero on the 27th The average temperature for Casper was 33.2 degrees which was 1.8
degrees below normal. The highest reading was 72 on the 21st. The lowest reading was 9 below zero on the 10th.

       Total precipitation for the month was 1.00 inches which was 111 percent of normal. The monthly total snowfall of 17.5
incheswas 142 percent of normal. The greatest daily snowfall was 10.6 inches that fell on the 23rd.
      The highest wind gust was 58 mph out of the west southwest which occurred on the 5th.
 

APRIL 2009 – Colder and Wetter than Normal

     Significant snowstorms:

     April 3rd and 4th - 4 to 8 inches of snow in the Casper area.
      April 16th and 17th - 3 to 8 inches of snow in the Casper area
      April 26th and 27th - 4 to 9 inches of snow in the Casper area.
         


      The average temperature for Casper was 40.0 degrees which was 2.7 degrees below normal.
The highest reading was 77 degrees which occurred on the 23rd. The lowest reading was 14
degrees which occurred on the 5th. No daily temperature records were set during the month of
April.


       Total precipitation for the month was 2.05 inches which was 135 percent of normal. The greatest daily
precipitation was 0.50 inches on the 25th. The total snowfall for the month was 16.5 inches inches which
was 120 percent of normal.

     The peak wind gust was 49 mph out of the southwest on the 25th.
 

MAY 2009 – 3rd Driest May on Record, Slightly Warmer than Normal

       The average temperature for Casper was 52.9 degrees which was 0.8 degrees above normal. The highest reading was 89 degrees which occurred on the 19th.  The lowest reading was 24 degrees which occurred on the 13th.  Two daily
record highs were set during the month, 88 degrees on the 18th and 89 degrees on the 19th.  A record low of 25 was set on the 16th.

      Total precipitation for the month was 0.43 inches which was only 18 percent of normal.  No daily precipitation records were set.  Only a trace of snow fell during the month. 

      The highest wind gust was 59 mph out of the west southwest which occurred on the 12th.
 
JUNE 2009 – Cooler and Wetter than Normal

      The average temperature for Casper was 59.5 degrees which was 3.2 degrees below normal. The highest reading was 94 degrees on the 30th.  The lowest reading was 36 on the 8th.  No daily record temperatures were set during the month.

      Total precipitation for the month was 2.23 inches which was 156 percent of normal. The greatest daily rainfall was 0.57 inches that fell on the 13th. The highest wind gust was 54 mph out of the west southwest on the 6th.

 
JULY 2009  – Second Wettest July on Record, Flash Flooding on July 3rd , Fourth Coolest on Record

      The main headline for Casper during July 2009 was a flash flood that struck the town on the evening of the 3rd.  A thunderstorm dumped over two inches of rain within 30 minutes on sections of Casper resulting in extensive flash flooding.  1.61 inches of rain fell at the airport setting a new daily precipitation record with one location on the north side of town reporting 2.26 inches of rainfall on the 3rd (the all-time daily precipitation record for Casper was 2.22 inches on May 17, 2000).   The record 24 hour precipitation for the month of July occurred on July 22, 1983 when 1.78 inches of rain fell at the airport.  The official amount of 1.61 inches of rainfall at the airport was the third highest daily total in the month of July on record.

     The average temperature for Casper was 66.7 degrees which was 3.3 degrees below normal and the fourth coolest July on record.  The coldest July occurred in 1972 with an average temperature of 65.9 degrees.  The highest reading was 95 degrees which occurred on the 23rd.  The lowest reading was 40 degrees which occurred on the 30th. 
A record low temperature of 42 degrees was set on the 15th.

      Total precipitation for the month was 3.45 inches which was 267 percent of normal and the second wettest July on record.  The wettest July on record occurred in 2007 with 3.54 inches of rainfall.

     The highest wind gust was 52 mph out of the northwest on the 19th.
 
AUGUST 2009  – Fourth Coldest on Record, Tenth Wettest on Record

      The average temperature for Casper was 65.4 degrees which was 3.2 degrees below normal, the fourth coldest on record.  The coldest August on record occurred in 1974 with an average monthly temperature of 64.4 degrees.  The highest reading for August and 2009 was 97 degrees which occurred on the 22nd, and this reading also set a new record high for the date.   The lowest reading was 36 which occurred on the 17th, and this reading tied the record low for the date.   Record lows were set on the 16th (38 degrees) and on the 18th (37 degrees).

      Total precipitation for the month was 1.34 inches which was 184 percent of normal, the tenth wettest August on record.  The greatest daily rainfall was 0.46 inches that fell on the 15th, setting a new daily precipitation record.  The 0.20 inches of rain that fell on the 24th also set a daily precipitation record.

     The highest wind gust was 55 mph out of the north northwest which occurred on the 3rd.

 

SEPTEMBER 2009  – Another Wet Month, Warmer than Normal

     The average temperature for Casper was 59.3 degrees which was 1.7 degrees above normal. The highest reading was 91 degrees which occurred on the 4th while the lowest reading was 26 which occurred on the 28th.  A new record high temperature of 86 degrees occurred on the very next day, the 29th No record lows were set during the month.

     Total precipitation for the month was 1.62 inches which was 165 percent of normal.  The greatest daily precipitation was 0.90 inches that fell on the 20th.  No daily precipitation records were set during September.  1.3 inches of snow fell on the last day of the month which was also the monthly total, 65 percent of normal.

     The highest wind gust was 68 mph out of the northeast and associated with a thunderstorm on the 20th.

 

OCTOBER 2009 – Coldest October on Record, Seventh Snowiest on Record

     An early taste of Winter hit Casper on October 9-11 when the airport received 8.4 inches of snow and 
temperatures plunged into the 20s for highs and lows in the teens.
   

        The average temperature for Casper was 37.0 degrees which was 8.7 degrees below average, the coldest October on record.  October 1969 held the previous record with an average monthly temperature of 37.8 degrees.  The highest reading was 75 degrees which occurred on the 18th.  The lowest reading was 11 degrees which occurred on the 10th.   Record lows were set on the 3rd (22 degrees), the 9th (12 degrees), the 10th (11 degrees), and the 11th (16 degrees).  

      Total precipitation for the month was 1.27 inches which was 111 percent of normal. The greatest daily precipitation  was 0.41 inches that fell on the 4th. Total snowfall for October was 13.8 inches which was 194 percent of normal and the seventh snowiest October on record.  The snowiest October on record was in 1949 when 22.1 inches of snow fell during the month.  The greatest daily snowfall for the month was 5.2 inches which fell on the 9th.

     The peak wind gust for the month was 47 mph out of the southwest which occurred on the 27th.

 
NOVEMBER 2009 –  Second Driest (tie), Fourth Least Snowiest, 11th Warmest

       The average temperature for Casper was 38.4 degrees which was 6.4 degrees above normal. The highest reading was 71 degrees which occurred on the 5th, also a new record high for the date. The lowest reading was 8 degrees which occurred on the 15th.   No other record temperatures were set during the month.

      Total precipitation for the month was 0.05 inches which was only 6 percent of normal and the second driest November on record.  The driest November occurred in 1949 when only 0.04 inches of precipitation fell.  The greatest daily precipitation was 0.04 inches on the 23rd.  Total snowfall was 0.6 inches which was only 5 percent of normal and  the fourth least snowiest November on record.  No snowfall was recorded in November 1949 and 1997.

 

DECEMBER 2009 – Third Coldest, Fifth Wettest, Fourth Snowiest

Significant snowstorms:

Cold and Snowy Start to Month - 4 Inches of Snow in Casper area
Another 3 to 5 Inches of Snowfall on December 5-6

3 to 6 Inches of Snowfall on December 23rd

4 to 8 inches of Additional Snowfall Christmas and the 26th

 

     The average temperature for Casper was 15.6 degrees which was 8.2 degrees below normal, making December 2009 the third coldest on record.  The coldest December on record was in 1983 with an average monthly temperature of 10.9 degrees.  The second coldest December was in 1978 with an average monthly temperature of 13.2 degrees. The highest reading was 46 degrees which occurred on the 21st and 22nd.  The lowest reading for the month and year was 29 below zero on the 8th, also setting a record low for the date. Casper also set a record low on Christmas Day at 15 below zero.

      Total precipitation for the month was 0.97 inches which was 156 percent of normal, the fifth wettest December on record.  The wettest December on record was in 1982 when 3.71 inches of precipitation was recorded. The greatest daily precipitation was 0.24 inches on the 23rd.

     Total snowfall for December was 19.5 inches which was 164 percent of normal, and the fourth snowiest December on record.  The snowiest December on record was also in 1982 when 62.8 inches of snow fell.  The most daily snowfall was recorded on the 26th with 6.3 inches.

      The highest wind gust was 48 mph out of the southwest on the 12th.
 

 

 
 
 
 
 
 
 

 

















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