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Mason City, IL Weather & Growing Conditions

Overnight
70°F
Partly Cloudy
Partly cloudy, with a low around 70. South southeast wind around 7 mph.

7-day forecast

WhenTempForecastWindPrecip
Overnight 70°F Partly Cloudy 7 mph SSE 4%
Saturday 88°F Mostly Cloudy 7 mph S 14%
Saturday Night 68°F Chance Showers And Thunderstorms 6 mph SW 43%
Sunday 79°F Chance Showers And Thunderstorms then Showers And Thunderstorms Likely 3 to 10 mph N 66%
Sunday Night 60°F Showers And Thunderstorms Likely then Chance Showers And Thunderstorms 9 to 14 mph NE 68%
Monday 67°F Showers And Thunderstorms Likely 13 mph NE 68%
Monday Night 54°F Chance Rain Showers 9 to 14 mph NE 46%
Tuesday 65°F Slight Chance Rain Showers 12 mph NE 22%
Tuesday Night 51°F Partly Cloudy 6 to 12 mph NNE 12%
Wednesday 69°F Mostly Sunny 9 mph NNE 3%
Wednesday Night 53°F Partly Cloudy 3 to 8 mph NNE 2%
Thursday 71°F Mostly Sunny 7 mph NNE 3%
Thursday Night 55°F Partly Cloudy 6 mph NNE 3%
Friday 74°F Mostly Sunny 3 to 7 mph NE 3%

Forecast source: National Weather Service (api.weather.gov). Updated through the day.

Growing snapshot for Mason City, IL

Last spring frost
Apr 17
First fall frost
Oct 18
Growing season
182 days
Hardiness zone
6a

Explore more for Mason City, IL: full frost dates · planting calendar · Illinois frost dates

Climate data from the nearest NOAA station, Mason City 4Se, Il (5.1 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.