Mercer, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mercer, a community in Iron County, Wisconsin.
Overnight
56°F
Light Rain Likely
Rain likely and patchy fog. Cloudy, with a low around 56. East wind around 5 mph. Chance of precipitation is 70%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Mercer
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 56°F | Light Rain Likely | 5 mph E | 70% |
| Wednesday | 60°F | Light Rain | 5 mph S | 83% |
| Wednesday Night | 38°F | Light Rain | 5 to 15 mph W | 85% |
| Thursday | 43°F | Light Rain then Slight Chance Rain And Snow | 15 mph N | 81% |
| Thursday Night | 23°F | Chance Rain And Snow | 5 to 15 mph N | 28% |
| Friday | 41°F | Partly Sunny | 5 to 10 mph N | 9% |
| Friday Night | 22°F | Partly Cloudy | 0 mph | 0% |
| Saturday | 43°F | Mostly Sunny | 0 to 5 mph W | 0% |
| Saturday Night | 25°F | Partly Cloudy | 5 mph W | 10% |
| Sunday | 48°F | Slight Chance Light Rain | 5 to 10 mph W | 17% |
| Sunday Night | 27°F | Partly Cloudy | 0 to 5 mph W | 6% |
| Monday | 53°F | Partly Sunny | 5 to 10 mph SW | 1% |
| Monday Night | 30°F | Partly Cloudy | 5 to 10 mph W | 3% |
| Tuesday | 50°F | Slight Chance Light Rain then Mostly Sunny | 5 to 10 mph NW | 15% |
Forecast source: National Weather Service (api.weather.gov) for Mercer (46.161, -90.042). Updated through the day.
Growing snapshot for Mercer
Last spring frost
May 25
First fall frost
Sep 21
Growing season
117 days
Hardiness zone
4a
More local growing data for Mercer: nearby ZIP 54547 weather · frost dates · planting calendar · Wisconsin frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Rest Lake, Wi (12.6 mi from Mercer). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.