Weather history and climate summary information is available for the following locations:
- LaCrosse
- Madison
- Milwaukee
Warmest September Days
The warmest September days in Wisconsin are:
| LaCrosse, Wisconsin | 1955 | 100.4°F |
| LaCrosse, Wisconsin | 1978 | 100°F |
| Madison, Wisconsin | 1953 | 99.3°F |
| LaCrosse, Wisconsin | 1998 | 98.6°F |
| Milwaukee, Wisconsin | 1953 | 98.4°F |
Coldest September Days
The coldest September days in Wisconsin were:
| LaCrosse, Wisconsin | 1949 | 23.4°F |
| Madison, Wisconsin | 1974 | 25°F |
| Madison, Wisconsin | 1949 | 25.3°F |
| Madison, Wisconsin | 1976 | 25.9°F |
| Madison, Wisconsin | 1984 | 26.1°F |
Wettest September Days
The wettest single days in September occurred:
| Madison, Wisconsin | 1992 | 10.7 inches |
| Milwaukee, Wisconsin | 1992 | 10.4 inches |
| Madison, Wisconsin | 2009 | 3.7 inches |
| LaCrosse, Wisconsin | 1983 | 3.5 inches |
| LaCrosse, Wisconsin | 2004 | 3.2 inches |