Grantsburg, WI Weather & Growing Conditions
Overnight
52°F
Chance Rain Showers
A chance of rain showers and patchy fog. Cloudy. Low around 52, with temperatures rising to around 54 overnight. East wind around 5 mph, with gusts as high as 20 mph. Chance of precipitation is 40%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 52°F | Chance Rain Showers | 5 mph E | 39% |
| Saturday | 62°F | Chance Rain Showers then Patchy Fog | 5 to 10 mph NE | 27% |
| Saturday Night | 48°F | Mostly Cloudy then Patchy Fog | 5 mph NE | 5% |
| Sunday | 65°F | Mostly Cloudy | 5 to 10 mph NE | 0% |
| Sunday Night | 42°F | Mostly Cloudy | 5 to 10 mph NE | 0% |
| Monday | 65°F | Partly Sunny | 5 mph E | 0% |
| Monday Night | 40°F | Partly Cloudy | 0 to 5 mph NE | 2% |
| Tuesday | 67°F | Sunny | 0 to 5 mph E | 2% |
| Tuesday Night | 38°F | Mostly Clear | 0 to 5 mph E | 1% |
| Wednesday | 68°F | Sunny | 0 to 5 mph SE | 0% |
| Wednesday Night | 42°F | Mostly Clear | 0 mph | 3% |
| Thursday | 69°F | Mostly Sunny | 0 to 5 mph SE | 6% |
| Thursday Night | 45°F | Partly Cloudy | 0 mph | 4% |
| Friday | 72°F | Mostly Sunny | 0 to 5 mph SE | 4% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Grantsburg, WI
Last spring frost
May 11
First fall frost
Oct 1
Growing season
141 days
Hardiness zone
4a
Explore more for Grantsburg, WI: full frost dates · planting calendar · Wisconsin frost dates
Climate data from the nearest NOAA station, Grantsburg, Wi (1.5 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.