Grantsburg, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Grantsburg, a village in Burnett County, Wisconsin.
Overnight
50°F
Rain Showers
Rain showers and patchy fog. Cloudy, with a low around 50. East wind around 5 mph, with gusts as high as 20 mph. Chance of precipitation is 40%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Grantsburg
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 50°F | Rain Showers | 5 mph E | 44% |
| Saturday | 64°F | Chance Rain Showers then Patchy Fog | 5 mph NE | 27% |
| Saturday Night | 47°F | Mostly Cloudy | 5 mph NE | 5% |
| Sunday | 67°F | Mostly Cloudy | 5 to 10 mph NE | 0% |
| Sunday Night | 42°F | Mostly Cloudy | 5 to 10 mph NE | 0% |
| Monday | 65°F | Mostly Cloudy | 5 mph E | 0% |
| Monday Night | 39°F | Partly Cloudy | 0 to 5 mph NE | 1% |
| Tuesday | 66°F | Mostly Sunny | 0 to 5 mph E | 1% |
| Tuesday Night | 40°F | Mostly Clear | 0 to 5 mph E | 1% |
| Wednesday | 68°F | Sunny | 0 to 5 mph SE | 0% |
| Wednesday Night | 44°F | Partly Cloudy | 0 mph | 8% |
| Thursday | 70°F | Mostly Sunny | 0 to 5 mph S | 11% |
| Thursday Night | 46°F | Partly Cloudy | 0 mph | 8% |
| Friday | 72°F | Mostly Sunny | 0 to 5 mph SE | 6% |
Forecast source: National Weather Service (api.weather.gov) for Grantsburg (45.784, -92.677). Updated through the day.
Growing snapshot for Grantsburg
Last spring frost
May 11
First fall frost
Oct 1
Growing season
141 days
Hardiness zone
4a
More local growing data for Grantsburg: nearby ZIP 54840 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Grantsburg, Wi (1.5 mi from Grantsburg). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.