Mercer, WI Weather & Growing Conditions
Overnight
55°F
Widespread Fog
Widespread fog and rain showers likely. Cloudy. Low around 55, with temperatures rising to around 57 overnight. Southeast wind around 5 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 55°F | Widespread Fog | 5 mph SE | 63% |
| Wednesday | 61°F | Widespread Fog then Rain Showers | 7 mph SSE | 85% |
| Wednesday Night | 36°F | Rain Showers | 3 to 12 mph W | 86% |
| Thursday | 43°F | Rain Showers then Slight Chance Rain And Snow Showers | 16 mph N | 82% |
| Thursday Night | 24°F | Chance Rain And Snow Showers then Cloudy | 7 to 13 mph N | 36% |
| Friday | 40°F | Partly Sunny | 3 to 8 mph NNE | 9% |
| Friday Night | 23°F | Partly Cloudy | 2 mph N | 0% |
| Saturday | 43°F | Mostly Sunny | 0 to 6 mph W | 0% |
| Saturday Night | 26°F | Partly Cloudy | 6 mph WSW | 9% |
| Sunday | 48°F | Slight Chance Rain Showers | 6 to 10 mph WNW | 17% |
| Sunday Night | 27°F | Partly Cloudy | 2 to 6 mph WSW | 7% |
| Monday | 52°F | Partly Sunny | 5 to 12 mph SW | 1% |
| Monday Night | 31°F | Partly Cloudy | 5 to 8 mph W | 3% |
| Tuesday | 50°F | Slight Chance Rain Showers then Mostly Sunny | 5 to 9 mph WNW | 15% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mercer, WI
Last spring frost
May 25
First fall frost
Sep 21
Growing season
117 days
Hardiness zone
4a
Explore more for Mercer, WI: full frost dates · planting calendar · Wisconsin frost dates
Climate data from the nearest NOAA station, Rest Lake, Wi (1.4 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.