Jefferson, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Jefferson, a city in Jefferson County, Wisconsin.
Today
83°F
Partly Sunny then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 4pm. Partly sunny, with a high near 83. Southwest wind around 10 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Jefferson
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 83°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 10 mph SW | 19% |
| Tonight | 63°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 to 10 mph W | 92% |
| Wednesday | 75°F | Patchy Fog then Slight Chance Showers And Thunderstorms | 5 mph W | 65% |
| Wednesday Night | 58°F | Chance Showers And Thunderstorms | 0 to 5 mph NW | 37% |
| Thursday | 79°F | Slight Chance Rain Showers then Mostly Sunny | 0 to 5 mph W | 19% |
| Thursday Night | 57°F | Mostly Clear | 0 mph | 7% |
| Friday | 81°F | Mostly Sunny | 0 to 5 mph SW | 2% |
| Friday Night | 62°F | Mostly Clear | 0 to 5 mph SW | 5% |
| Saturday | 84°F | Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 15% |
| Saturday Night | 67°F | Slight Chance Showers And Thunderstorms | 5 mph SW | 30% |
| Sunday | 85°F | Chance Showers And Thunderstorms | 10 mph SW | 30% |
| Sunday Night | 66°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 48% |
| Monday | 83°F | Chance Rain Showers | 5 mph S | 46% |
| Monday Night | 65°F | Chance Showers And Thunderstorms | 5 mph W | 44% |
Forecast source: National Weather Service (api.weather.gov) for Jefferson (43.004, -88.808). Updated through the day.
Growing snapshot for Jefferson
Last spring frost
Apr 25
First fall frost
Oct 18
Growing season
173 days
Hardiness zone
5b
More local growing data for Jefferson: nearby ZIP 53549 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Fort Atkinson
Hebron
Helenville
Ixonia
Johnson Creek
Lake Mills
Palmyra
Rome
Sullivan
Waterloo
Watertown
Climate data from the nearest NOAA station, Jefferson Wwtp, Wi (2.1 mi from Jefferson). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.