Mason City, IL Weather & Growing Conditions
Tonight
53°F
Rain
Rain before 4am, then a slight chance of rain showers between 4am and 5am. Mostly cloudy, with a low around 53. South southwest wind around 14 mph, with gusts as high as 22 mph. Chance of precipitation is 80%. New rainfall amounts between a half and three quarters of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 53°F | Rain | 14 mph SSW | 75% |
| Wednesday | 59°F | Mostly Cloudy | 12 to 15 mph SW | 12% |
| Wednesday Night | 44°F | Mostly Cloudy | 10 mph SW | 1% |
| Thursday | 60°F | Mostly Sunny | 8 to 13 mph WSW | 6% |
| Thursday Night | 42°F | Mostly Cloudy then Slight Chance Light Rain | 7 mph NW | 23% |
| Friday | 55°F | Mostly Cloudy | 7 to 10 mph NNW | 14% |
| Friday Night | 35°F | Mostly Cloudy | 2 to 8 mph NNW | 2% |
| Saturday | 54°F | Mostly Sunny | 5 mph NW | 2% |
| Saturday Night | 34°F | Partly Cloudy | 3 mph W | 1% |
| Sunday | 60°F | Sunny | 3 to 8 mph W | 10% |
| Sunday Night | 34°F | Mostly Clear | 6 mph W | 5% |
| Monday | 64°F | Sunny | 3 to 10 mph SW | 2% |
| Monday Night | 39°F | Mostly Clear | 7 mph WSW | 1% |
| Tuesday | 66°F | Sunny | 6 mph WNW | 1% |
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 Nov 4, 2026.