October 2009 Climatic Summary

October 2009 was one of the coldest October’s on record. Temperatures averaged 7 to 9 degrees below normal, with all sites reporting below normal temperatures. Spearfish was the warm spot averaging 6.1 degrees below normal. The cold spot was at Mt. Rushmore where temperatures averaged 11.1 degrees below normal. The following locations reported the coldest October’s on record: Bison, Cottonwood 2E, Devils Tower, Fort Meade, Long Valley, Maurine 12SW, Milesville 5NE, Mission 14S, Mt. Rushmore, Oelrichs, Pactola Dam, Rapid City Region Airport, Winner and Wood.
October was also a wet and snowy month. Precipitation average 80 to 100 percent above normal. Colony in northeast Wyoming was the only location to report below normal precipitation. The wet spot was at Porcupine 1N where precipitation was 328 percent of normal. Colony in northeast Wyoming was the dry spot with 83 percent of normal precipitation. The precipitation surplus for the month averaged 1.29 inches.
Snowfall was heavy over the Black Hills. In the northern Black Hills 3 to 4 feet of snow was reported, while the southern and central Black Hills reported 1 to 2 feet. Across northeast Wyoming, northwest and southwest South Dakota 6 to 12 inches of snow fell. Elsewhere on the South Dakota plains snowfall was generally less than 6 inches.
 
 

October storm summary...

 
On October 1…A strong upper level storm system brought strong winds to the plains of western South Dakota and 2 to 4 inches of snow to the northern Black Hills and Bear Lodge Mountains. Winds of 35 to 45 mph with gusts to 60 mph were common on the plains. The strongest winds reported were 70 mph at Ellsworth AFB and 66 mph in downtown Rapid City.
 
On October 4 and 5…Another strong upper level storm system brought snow to the northern and central Black Hills, northeast Wyoming and far northwest South Dakota.
In the northern and central Black Hills 4 to 8 inches of snow fell. In northwest South Dakota 2 to 5 inches of snow fell, while in northeast Wyoming 2 to 5 inches of snow
fell in Crook County and over northern Campbell County.
 
On October 7 and 8…Another strong upper level storm system brought more snow to northeast Wyoming, the Black Hills and extreme southwest South Dakota. In the
northern and central Black Hills 4 to 8 inches of snow fell. In southwest South Dakota 1 to 2 inches of snow fell, and in Crook County and northern Campbell County 1 to
3 inches of snow was reported.
 
On October 11…A weak upper level storm system brought 2 to 5 inches of snow to northern Campbell County and northern Crook County in northeast Wyoming.
 
On October 25…A weak upper level storm system brought 3 to 6 inches of snow to the northern Black Hills and Bear Lodge Mountains.
 
On October 28 and 29…A strong upper level low pressure system brought snow to southwest South Dakota…and heavy snows to the northern and central Black Hills, and northern foothills. In the northern and central Black Hills 8 to 15 inches of snow fell with locally heavier amounts around Lead and Deadwood. Lead reported 23. 4 inches of snow, with 18.6 inches in Deadwood. In the northern foothills 5 to 9 inches of snow fell. Across southwest South Dakota 4 to 6 inches of snow fell. 

 

LOCAL EXTREMES

Temperature Data

Rapid City

 

Lead

 

Gillette

 

 

Temperature

Date

Temperature

Date

Temperature 

Date

Maximum Temperature

81 degrees

18th

72 degrees

18th

76 degrees

18th

Minimum Temperature

11 degrees

10th

7 degrees

10th

10 degrees

10th

Precipitation Data

Rapid City

 

Lead

 

Gillette

 

Monthly Data

Amount

Data

Amount

Date

Amount

Date

Precipitation

1.97 inches

 

5.44 inches

 

1.97 inches

 

Snowfall

8.5 inches

 

53.3 inches

 

15.0 inches

 

 

 

 

 

 

 

 

Daily Data

 

 

 

 

 

 

Maximum Precipitation

0.61 inches

5th

1.04 inches

29th

0.75 inches

5th

Maximum Snowfall

3.2 inches

29th

17.3 inches

29th

6.0 inches

5th

REGIONAL EXTREMES

Temperature Data

 

Western South Dakota

 

 

Northeastern Wyoming

 

 

Temperature

Site

Date

Temperature

Site

Date

Maximum Temperature

84 degrees

Ardmore 2N
 Winner

18th
18th

81 degrees

Upton

18th

Minimum Temperature

0 degrees

Custer

10th

0 degrees

Upton 14 ENE

10th

Precipitation Data

 

Western South Dakota

 

 

Northeastern Wyoming

 

Monthly Data

Amount

Site

Date

Amount

Site

Date

Maximum Precipitation

5.44 inches

Lead

 

2.66 inches

Upton 14 ENE

 

Minimum Precipitation

1.61 inches

Harding 3SE

 

1.08 inches

Colony

 

Maximum Snowfall

53.3 inches

Lead

 

20.4 inches

Upton 14 ENE

 

Minimum Snowfall

0.6 inches

Interior 3NE

 

2.0 inches

Newcastle

 

 

 

 

 

 

 

 

Daily Data

 

 

 

 

 

 

Maximum Precipitation

1.54 inches

Interior 3NE

5th

0.77 inches

Upton 14 ENE

5th

Maximum Snowfall

17.3 inches

Lead

29th

6.0 inches

Gillette 4SE

5th

MONTHLY RECORDS

 

LOCATION

DATE

NEW RECORD

OLD RECORD

DATE

Bison

October

38.6 degree average temperature

39.1 degree average temperature

2002

Cottonwood 2E

October

40.1 degree average temperature

40.6 degree average temperature

2002

Devils Tower, WY

October

36.4 degree average temperature

38.5 degree average temperature

1969

Ft. Meade

October

39.9 degree average temperature

39.9 degree average temperature

2002

Long Valley

October

40.6 degree average temperature

41.6 degree average temperature

2002

Maurine 12SW

October

38.9 degree average temperature

39.2 degree average temperature

2002

Milesville 5NE

October

40.7 degree average temperature

43.2 degree average temperature

1969

Mission 14S

October

38.4 degree average temperature

40.7 degree average temperature

2002

Mt. Rushmore

October

35.2 degree average temperature

37.3 degree average temperature

2002

Mt. Rushmore

October

19.4 inches of snow

19.0 inches of snow

1996

Oelrichs

October

39.7 degree average temperature

41.9 degree average temperature

2002

Pactola Dam

October

34.2 degree average temperature

36.2 degree average temperature

2002, 1969

Rapid City Airport

October

38.7 degree average temperature

39.0 degree average temperature

2002

Winner

October

42.6 degree average temperature

44.6 degree average temperature

2002

Wood

October

39.7 degree average temperature

41.6 degree average temperature

2002

 Return to Climate Summaries


USA.gov is the U.S. government's official web portal to all federal, state and local government web resources and services.