Mercer, WI Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mercer, a community in Iron County, Wisconsin.
Overnight
64°F
Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms. Mostly cloudy. Low around 64, with temperatures rising to around 67 overnight. Southwest wind around 10 mph, with gusts as high as 25 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Mercer
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 64°F | Slight Chance Showers And Thunderstorms | 10 mph SW | 20% |
| Tuesday | 75°F | Chance Showers And Thunderstorms then Partly Sunny | 5 to 10 mph W | 50% |
| Tuesday Night | 50°F | Mostly Cloudy | 0 to 5 mph NW | 4% |
| Wednesday | 74°F | Sunny | 0 to 5 mph W | 0% |
| Wednesday Night | 51°F | Mostly Clear | 0 to 5 mph SW | 0% |
| Thursday | 80°F | Sunny | 5 to 10 mph SW | 2% |
| Thursday Night | 59°F | Mostly Clear | 5 to 10 mph SW | 4% |
| Friday | 83°F | Sunny then Slight Chance Showers And Thunderstorms | 5 to 10 mph SW | 16% |
| Friday Night | 59°F | Chance Showers And Thunderstorms | 5 to 10 mph SW | 44% |
| Saturday | 79°F | Mostly Sunny then Slight Chance Showers And Thunderstorms | 5 mph SW | 19% |
| Saturday Night | 57°F | Slight Chance Showers And Thunderstorms then Chance Showers And Thunderstorms | 0 to 5 mph W | 49% |
| Sunday | 78°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 0 to 10 mph W | 49% |
| Sunday Night | 55°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 0 to 5 mph NW | 28% |
| Monday | 77°F | Slight Chance Rain Showers then Slight Chance Showers And Thunderstorms | 0 to 5 mph N | 23% |
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 Aug 4, 2026.