Weather history and climate summary information is available for the following locations:
- Caribou
- Millinocket
- Portland
- Presque Isle
Warmest September Days
The warmest September days in Maine are:
| Portland, Maine | 1983 | 95°F |
| Portland, Maine | 2010 | 93.9°F |
| Millinocket, Maine | 1943 | 93.4°F |
| Portland, Maine | 1973 | 93.2°F |
| Millinocket, Maine | 1999 | 93°F |
Coldest September Days
The coldest September days in Maine were:
| Caribou, Maine | 1978 | 23°F |
| Caribou, Maine | 1980 | 23°F |
| Presque Isle, Maine | 1947 | 23.4°F |
| Presque Isle, Maine | 2008 | 24.8°F |
| Presque Isle, Maine | 1956 | 25°F |
Wettest September Days
The wettest single days in September occurred:
| Portland, Maine | 1992 | 12.3 inches |
| Portland, Maine | 2008 | 5.5 inches |
| Portland, Maine | 1994 | 4.4 inches |
| Portland, Maine | 1999 | 4.4 inches |
| Millinocket, Maine | 1999 | 3.3 inches |