Sullivan, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Sullivan, a village in Jefferson County, Wisconsin.
This Afternoon
69°F
Rain Showers Likely
Rain showers likely. Cloudy. High near 69, with temperatures falling to around 64 in the afternoon. South wind around 15 mph, with gusts as high as 25 mph. Chance of precipitation is 70%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Sullivan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| This Afternoon | 69°F | Rain Showers Likely | 15 mph S | 72% |
| Tonight | 58°F | Rain Showers | 10 to 15 mph S | 93% |
| Wednesday | 62°F | Rain Showers | 10 to 15 mph S | 84% |
| Wednesday Night | 46°F | Chance Rain Showers then Chance Light Rain | 10 mph SW | 54% |
| Thursday | 54°F | Light Rain Likely | 5 to 10 mph W | 74% |
| Thursday Night | 38°F | Chance Light Rain | 5 to 10 mph NW | 52% |
| Friday | 49°F | Slight Chance Light Rain then Mostly Cloudy | 5 to 15 mph N | 20% |
| Friday Night | 31°F | Partly Cloudy | 0 to 5 mph N | 2% |
| Saturday | 52°F | Mostly Sunny | 0 to 5 mph W | 4% |
| Saturday Night | 32°F | Partly Cloudy | 0 to 5 mph W | 8% |
| Sunday | 57°F | Slight Chance Light Rain | 5 to 10 mph W | 17% |
| Sunday Night | 34°F | Mostly Clear | 5 mph W | 5% |
| Monday | 59°F | Mostly Sunny | 5 to 10 mph SW | 1% |
| Monday Night | 38°F | Mostly Clear | 5 to 10 mph W | 1% |
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 Nov 4, 2026.