Fort Sill, OK Climate

Summary Graph

The summary climate graph for Fort Sill, OK shows a selection of temperature, rainfall and snow minimum, mean and maximum measures over the course of a year. Click on each of the measures in the key to toggle them on and off.

Graph of average and extreme temperature ranges by day for Fort Sill, OK.


The warmest month in Henry Post Army Air Field, Fort Sill, Oklahoma is July with an average high temperature of 95.1°F. The hottest day on record was June 14 1953 when the temperature hit 111.9°F. During January the overnight temperature drops to an average of 29.6°F with the lowest temperature of -5.6°F being recorded on January 4 1947.

Warmest Days

Warmest Months

Coldest Days

Coldest Months

The warmest days on record are:

14 Jun 1953111.9°F
2 Aug 2012111.9°F
22 Jul 1974111°F
9 Jul 2011110.8°F
5 Aug 2011110.7°F

The warmest months on average were:

August 2011106.3°F
July 2011105.3°F
July 1998102.7°F
August 1956102.5°F
July 1954102°F

The coldest days on record are:

4 Jan 1947-5.6°F
23 Dec 1989-4.9°F
8 Jan 1988-3.8°F
10 Jan 1977-1.8°F
8 Jan 1940-1.7°F

The coldest months on average were:

January 194019.6°F
January 196320.5°F
January 197921.8°F
January 197821.9°F
December 198322.3°F


The wettest month in Fort Sill, OK is May with an average of 2.6 inches of rain falling on 10 to 11 days. The driest month in Fort Sill, OK is January with an average of 0.6 inches of rain falling on 6 to 7 days.

Wettest Days

The wettest days on record are:

18 September 20065.1 inches
15 September 19824.4 inches
29 September 19853.6 inches
25 September 19742.9 inches
4 September 19862.8 inches

Wettest Months

The wettest months on record are:

May 198216.2 inches
October 198315.3 inches
June 200714.8 inches
May 197511.8 inches
June 198910.6 inches

Driest Months

The driest months on record are:

October 19390 inches
November 19390 inches
December 19390 inches
January 19400 inches
February 19400 inches