Weather history and climate summary information is available for the following locations:
- Cincinnati
- Cleveland
- Columbus
- Dayton
- Wilmington
- Youngstown
Warmest May Days
The warmest May days in Ohio are:
| Dayton, Ohio | 1977 | 96.1°F |
| Columbus, Ohio | 2012 | 94.6°F |
| Columbus, Ohio | 2011 | 94.3°F |
| Dayton, Ohio | 2012 | 93.7°F |
| Dayton, Ohio | 1939 | 93.4°F |
Coldest May Days
The coldest May days in Ohio were:
| Youngstown, Ohio | 1963 | 25°F |
| Youngstown, Ohio | 1983 | 25°F |
| Youngstown, Ohio | 1978 | 25.2°F |
| Dayton, Ohio | 1966 | 26.1°F |
| Columbus, Ohio | 1966 | 26.1°F |
Wettest May Days
The wettest single days in May occurred:
| Dayton, Ohio | 1973 | 7.5 inches |
| Dayton, Ohio | 1989 | 3.6 inches |
| Cincinnati, Ohio | 2003 | 3.1 inches |
| Cincinnati, Ohio | 1986 | 2.7 inches |
| Cleveland, Ohio | 1989 | 2.4 inches |