Sullivan, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sullivan, a village in Jefferson County, Wisconsin.
Tonight
60°F
Showers And Thunderstorms
A chance of rain showers before 10pm, then showers and thunderstorms. Some of the storms could produce heavy rain. Cloudy, with a low around 60. East wind 10 to 15 mph. Chance of precipitation is 100%. New rainfall amounts between 1 and 2 inches possible.
7-day forecast for Sullivan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 60°F | Showers And Thunderstorms | 10 to 15 mph E | 95% |
| Saturday | 72°F | Showers And Thunderstorms | 10 to 15 mph SE | 94% |
| Saturday Night | 59°F | Showers And Thunderstorms Likely | 5 to 10 mph NE | 73% |
| Sunday | 67°F | Chance Rain Showers | 10 to 15 mph NE | 43% |
| Sunday Night | 53°F | Chance Rain Showers then Mostly Cloudy | 10 to 15 mph NE | 26% |
| Monday | 63°F | Slight Chance Rain Showers | 10 to 15 mph NE | 16% |
| Monday Night | 48°F | Mostly Cloudy | 5 to 10 mph NE | 14% |
| Tuesday | 61°F | Partly Sunny | 10 to 15 mph NE | 14% |
| Tuesday Night | 47°F | Partly Cloudy | 5 to 10 mph NE | 8% |
| Wednesday | 64°F | Partly Sunny | 5 to 10 mph NE | 8% |
| Wednesday Night | 48°F | Partly Cloudy | 0 to 5 mph NE | 4% |
| Thursday | 66°F | Partly Sunny | 0 to 5 mph NE | 3% |
| Thursday Night | 49°F | Partly Cloudy | 0 to 5 mph NE | 4% |
| Friday | 69°F | Mostly Sunny | 0 to 5 mph N | 4% |
Forecast source: National Weather Service (api.weather.gov) for Sullivan (43.012, -88.595). Updated through the day.
Growing snapshot for Sullivan
Last spring frost
May 3
First fall frost
Oct 9
Growing season
157 days
Hardiness zone
5b
More local growing data for Sullivan: nearby ZIP 53178 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Fort Atkinson
Hebron
Helenville
Ixonia
Jefferson
Johnson Creek
Lake Mills
Palmyra
Rome
Waterloo
Watertown
Climate data from the nearest NOAA station, Sullivan 3Se, Wi (4.9 mi from Sullivan). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.