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
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| 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.