The summary climate graph for Portland, ME 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 Portland International Jetport, Portland, Maine is July with an average high temperature of 80.8°F. The hottest day on record was August 2 1975 when the temperature hit 102.9°F. During January the overnight temperature drops to an average of 13.1°F with the lowest temperature of -20.9°F being recorded on February 11 1983.
The warmest days on record are:
| 2 Aug 1975 | 102.9°F |
| 23 Jul 2011 | 100°F |
| 28 Jun 1991 | 98.1°F |
| 18 Aug 1987 | 97°F |
| 16 Jun 1988 | 97°F |
The warmest months on average were:
| July 2011 | 85.1°F |
| July 1994 | 85°F |
| July 2010 | 84.1°F |
| August 1980 | 84°F |
| July 2006 | 83.6°F |
The coldest days on record are:
| 11 Feb 1983 | -20.9°F |
| 20 Dec 1975 | -20°F |
| 11 Jan 1976 | -20°F |
| 26 Dec 1980 | -20°F |
| 22 Jan 1984 | -18.9°F |
The coldest months on average were:
| January 1977 | 1.2°F |
| December 1989 | 1.3°F |
| January 1981 | 2.1°F |
| January 1982 | 3.7°F |
| January 1994 | 4.5°F |
The wettest month by average rainfall in Portland, ME is April with an average of 5.2 inches of rain falling on 13 to 14 days.Although in May it typically rains on more days with 4.5 inches falling in 14 to 15 days. The driest month in Portland, ME is February with an average of 3.3 inches of rain falling on 5 to 6 days.
The wettest days on record are:
| 24 June 1986 | 10.3 inches |
| 3 June 2012 | 5 inches |
| 2 June 1978 | 3.1 inches |
| 3 June 2001 | 2.9 inches |
| 6 June 1992 | 2.4 inches |
The wettest months on record are:
| September 1992 | 37.8 inches |
| August 1992 | 32.7 inches |
| July 1992 | 30.9 inches |
| April 1973 | 30.5 inches |
| May 1973 | 25.1 inches |
The driest months on record are:
| February 1987 | 0.1 inches |
| January 2004 | 0.2 inches |
| April 1999 | 0.3 inches |
| August 1995 | 0.5 inches |
| May 1975 | 0.6 inches |