The summary climate graph for San Antonio, TX 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.
The warmest month in Lackland Air Force Base Kelly Field Annex, San Antonio, Texas is August with an average high temperature of 95.8°F. The hottest day on record was August 28 2011 when the temperature hit 110.1°F. During January the overnight temperature drops to an average of 42.3°F with the lowest temperature of 3.9°F being recorded on January 31 1949.
The warmest days on record are:
| 28 Aug 2011 | 110.1°F |
| 15 Jun 1998 | 109.4°F |
| 26 Jul 1954 | 108°F |
| 25 Sep 2005 | 107.6°F |
| 8 Jul 1939 | 107.2°F |
The warmest months on average were:
| July 1998 | 102.6°F |
| August 2011 | 102.5°F |
| August 2006 | 101.1°F |
| July 2009 | 101.1°F |
| July 1980 | 101°F |
The coldest days on record are:
| 31 Jan 1949 | 3.9°F |
| 2 Feb 1951 | 9°F |
| 23 Dec 1989 | 9.1°F |
| 12 Jan 1962 | 10°F |
| 25 Dec 1983 | 13.1°F |
The coldest months on average were:
| January 1940 | 32.6°F |
| January 1962 | 33.6°F |
| January 1963 | 35.1°F |
| January 1977 | 35.7°F |
| December 1989 | 35.8°F |
The wettest month by average rainfall in San Antonio, TX is May with an average of 2.0 inches of rain falling on 11 to 12 days.Although in March it typically rains on more days with 1.0 inches falling in 11 to 12 days. The driest month by average rainfall in San Antonio, TX is December with an average of 0.8 inches of rain falling on 10 to 11 days. Although in July it typically rains on less days with 0.9 inches falling in 5 to 6 days
The wettest days on record are:
| 20 December 1991 | 4.9 inches |
| 23 December 1986 | 3.7 inches |
| 15 December 1992 | 1.5 inches |
| 25 December 1975 | 1.1 inches |
| 8 December 1997 | 1.1 inches |
The wettest months on record are:
| August 1974 | 15.1 inches |
| October 1998 | 13.9 inches |
| December 1991 | 13.7 inches |
| June 1981 | 13.5 inches |
| June 1987 | 10.7 inches |
The driest months on record are:
| August 1937 | 0 inches |
| September 1937 | 0 inches |
| October 1937 | 0 inches |
| November 1937 | 0 inches |
| December 1937 | 0 inches |