The summary climate graph for Key West, FL 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 Key West International, Key West, Florida is August with an average high temperature of 89.9°F. The hottest day on record was September 14 1980 when the temperature hit 102.9°F. During January the overnight temperature drops to an average of 63.7°F with the lowest temperature of 41.0°F being recorded on January 18 1981.
The warmest days on record are:
| 14 Sep 1980 | 102.9°F |
| 28 Sep 1979 | 100.9°F |
| 1 Aug 1988 | 100.9°F |
| 24 Jul 1977 | 98.1°F |
| 11 May 1996 | 98.1°F |
The warmest months on average were:
| August 2007 | 92.6°F |
| August 1990 | 92.3°F |
| July 2007 | 91.9°F |
| July 2009 | 91.9°F |
| August 1989 | 91.5°F |
The coldest days on record are:
| 18 Jan 1981 | 41°F |
| 12 Jan 2010 | 42.1°F |
| 27 Dec 1985 | 44.1°F |
| 25 Dec 1989 | 44.1°F |
| 24 Jan 2003 | 44.6°F |
The coldest months on average were:
| January 1981 | 53.5°F |
| February 1978 | 56.2°F |
| January 2003 | 56.2°F |
| December 2010 | 56.4°F |
| January 2001 | 56.7°F |
The wettest month by average rainfall in Key West, FL is October with an average of 6.3 inches of rain falling on 11 to 12 days.Although in August it typically rains on more days with 5.6 inches falling in 15 to 16 days. The driest month by average rainfall in Key West, FL is February with an average of 1.8 inches of rain falling on 6 to 7 days. Although in April it typically rains on less days with 3.7 inches falling in 5 to 6 days
The wettest days on record are:
| 16 March 1974 | 17.1 inches |
| 18 March 1973 | 7.9 inches |
| 7 March 1987 | 5.3 inches |
| 2 March 1979 | 2.1 inches |
| 4 March 2005 | 2 inches |
The wettest months on record are:
| April 1974 | 59.5 inches |
| January 1974 | 57.9 inches |
| October 1974 | 48.6 inches |
| November 1973 | 39.7 inches |
| March 1974 | 37.6 inches |
The driest months on record are:
| January 1990 | 0 inches |
| April 1998 | 0 inches |
| November 1995 | 0 inches |
| April 2006 | 0 inches |
| April 1988 | 0 inches |