Grantsburg, WI Weather & Growing Conditions
Today
56°F
Light Rain
Rain and patchy fog. Cloudy. High near 56, with temperatures falling to around 53 in the afternoon. South wind around 5 mph. Chance of precipitation is 80%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 56°F | Light Rain | 5 mph S | 83% |
| Tonight | 39°F | Light Rain | 0 to 15 mph N | 76% |
| Thursday | 46°F | Mostly Cloudy | 10 to 15 mph N | 7% |
| Thursday Night | 26°F | Mostly Cloudy | 0 to 5 mph N | 1% |
| Friday | 45°F | Sunny | 0 mph | 0% |
| Friday Night | 24°F | Partly Cloudy | 0 mph | 0% |
| Saturday | 47°F | Mostly Sunny | 0 to 5 mph SW | 0% |
| Saturday Night | 30°F | Partly Cloudy | 0 to 5 mph SW | 3% |
| Sunday | 53°F | Sunny | 0 to 5 mph W | 0% |
| Sunday Night | 32°F | Partly Cloudy | 0 to 5 mph SW | 0% |
| Monday | 59°F | Mostly Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 33°F | Mostly Clear | 0 to 5 mph W | 0% |
| Tuesday | 53°F | Mostly Sunny | 0 to 5 mph NW | 1% |
| Tuesday Night | 31°F | Partly Cloudy | 0 mph | 1% |
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 Nov 4, 2026.