Using over 550,000 weather observations from over 300 US weather stations to help you understand what the chance of rain...shine...snow is on any given day
The single hottest days in September occurred:
| Palm Springs, California | 1982 | 120.9°F |
| Palm Springs, California | 1990 | 118.9°F |
| Red Bluff, California | 1988 | 118°F |
| Palm Springs, California | 1993 | 117°F |
| Palm Springs, California | 2007 | 117°F |
The single coldest days in September occurred:
| Northway, Alaska | 1983 | -3.8°F |
| Northway, Alaska | 1992 | -3.1°F |
| Northway, Alaska | 1956 | -2°F |
| Bettles, Alaska | 2010 | 0°F |
| Delta Junction, Alaska | 1983 | 0.1°F |
The wettest single days in September occurred:
| Portland, Maine | 1992 | 12.3 inches |
| Seattle, Washington | 1978 | 12.1 inches |
| Raleigh-durham, North Carolina | 1976 | 11.7 inches |
| Lake Charles, Louisiana | 1979 | 11.1 inches |
| Madison, Wisconsin | 1992 | 10.7 inches |