Weather history and climate summary information is available for the following locations:
- Caribou
- Millinocket
- Portland
- Presque Isle
Warmest May Days
The warmest May days in Maine are:
| Caribou, Maine | 1977 | 95.9°F |
| Portland, Maine | 1987 | 93°F |
| Caribou, Maine | 1992 | 93°F |
| Portland, Maine | 2001 | 91.9°F |
| Caribou, Maine | 1978 | 91.9°F |
Coldest May Days
The coldest May days in Maine were:
| Caribou, Maine | 1974 | 18°F |
| Presque Isle, Maine | 1987 | 20.1°F |
| Presque Isle, Maine | 1956 | 21.9°F |
| Presque Isle, Maine | 1947 | 22.5°F |
| Caribou, Maine | 1978 | 23.9°F |
Wettest May Days
The wettest single days in May occurred:
| Caribou, Maine | 1986 | 10.8 inches |
| Portland, Maine | 1973 | 6 inches |
| Portland, Maine | 1989 | 3.9 inches |
| Portland, Maine | 2006 | 3.4 inches |
| Portland, Maine | 1991 | 2.2 inches |