September 2009 Climatic Summary

September was a warm month with temperatures averaging 2 to 4 degrees above normal. Spearfish was the warm spot averaging 6.7 degrees above normal. The cold spot was in Winner where temperatures averaged 0.9 degrees below normal.
September was a dry month with precipitation averaging only 60 to 70 percent of normal. The wettest area was across the northern and central Black Hills where precipitation averaged 100 to 150 percent of normal. The driest areas were across northern Campbell and Crook counties in northeast Wyoming, and across the central and northwestern plains of western South Dakota where precipitation was only 20 to 40 percent of normal. The wet spot was Glad Valley 2W,  where precipitation was 224 percent of normal. Kirley 6N was the dry spots with only 1 percent of normal precipitation. The precipitation deficit for the month averaged 0.47 inches.
A few locations in the central and northern Black Hills reported a trace of snow during the month of September.
 

September storm summary...

On September 8…Severe thunderstorms produced 60 mph winds 6 miles northeast of Wood in Mellette County and quarter size hail in Rosebud in Todd County.
 
On September 10…A line of severe thunderstorms moved across eastern Perkins County producing large hail from 16 miles southwest of Usta to Lemmon. The largest hail report was the size of golf balls 6 miles southeast of Shadehill Reservoir.
 
On September 11 to 14…an upper level low pressure system moved across western South Dakota producing 1.00 to 2.50 inches of rain across the central and northern Black Hills and the northern and eastern foothills. Across the plains of western South Dakota rainfall was generally 0.25 to 0.75 inches.


LOCAL EXTREMES   

Temperature Data

Rapid City

 

Lead

 

Gillette

 

 

Temperature

Date

Temperature

Date

Temperature 

Date

Maximum Temperature

91 degrees

5th

86 degrees

6th

92 degrees

4th

Minimum Temperature

32 degrees

28th

31 degrees

28th

25 degrees

28th

Precipitation Data

Rapid City

 

Lead

 

Gillette

 

Monthly Data

Amount

Data

Amount

Date

Amount

Date

Precipitation

1.90 inches

 

1.91 inches

 

0.41 inches

 

Snowfall

0.0 inches

 

0.0 inches

 

0.0 inches

 

 

 

 

 

 

 

 

Daily Data

 

 

 

 

 

 

Maximum Precipitation

1.40 inches

12th

1.20 inches

12th

0.17 inches

21st

Maximum Snowfall

0.0 inches

 

0.0 inches

 

0.0 inches

 

 
REGIONAL EXTREMES

Temperature Data

 

Western South Dakota

 

 

Northeast Wyoming

 

 

Temperature

Site

Date

Temperature

Site 

Date

Maximum Temperature

96 degrees

Cottonwood 2E

14th

94 degrees

Weston 1E

4th, 5th

Minimum Temperature

26 degrees

Hot Springs

28th

19 degrees

Upton 14ENE

27th, 28th

Precipitation Data

 

Western South Dakota

 

 

Northeast Wyoming

 

Monthly Data

Amount

Site

Date

Amount

Site

Date

Maximum Precipitation

2.75 inches

Rapid City 
4NW

 

0.88 inches

Upton 14ENE

 

Minimum Precipitation

0.02 inches

Kirley 6N

 

0.31 inches

Dillinger

 

Maximum Snowfall

Trace

Deadwood 2NE

 

0.0 inches

 

 

Minimum Snowfall

0.0 inches

 

 

0.0 inches

 

 

 

 

 

 

 

 

 

Daily Data 

 

 

 

 

 

 

Maximum Precipitation

2.17 inches

Glad Valley 2W

2nd

0.39 inches

Upton 14ENE

21st

Maximum Snowfall

Trace

Deadwood 2NE

21st

0.0 inhces

 

 

 

MONTHLY RECORDS 

LOCATION

DATE

NEW RECORD

OLD RECORD

DATE

 

 

NO RECORDS SET

 

 

 
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