Mason City, IL Weather & Growing Conditions
Today
87°F
Sunny
Sunny, with a high near 87. South wind around 6 mph.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 87°F | Sunny | 6 mph S | 0% |
| Tonight | 67°F | Partly Cloudy | 6 mph SSE | 6% |
| Wednesday | 86°F | Slight Chance Rain Showers then Chance Showers And Thunderstorms | 6 mph S | 28% |
| Wednesday Night | 67°F | Chance Showers And Thunderstorms then Showers And Thunderstorms | 5 mph SSE | 81% |
| Thursday | 82°F | Showers And Thunderstorms then Chance Showers And Thunderstorms | 5 mph S | 80% |
| Thursday Night | 65°F | Slight Chance Showers And Thunderstorms then Partly Cloudy | 3 mph SSE | 18% |
| Friday | 84°F | Mostly Sunny | 2 mph SSW | 6% |
| Friday Night | 66°F | Slight Chance Showers And Thunderstorms | 2 mph S | 22% |
| Saturday | 86°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 6 mph SSW | 15% |
| Saturday Night | 70°F | Mostly Clear | 2 to 6 mph S | 9% |
| Sunday | 89°F | Sunny | 7 to 10 mph SSW | 6% |
| Sunday Night | 72°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 9 mph SSW | 15% |
| Monday | 89°F | Slight Chance Showers And Thunderstorms then Mostly Sunny | 9 mph SSW | 15% |
| Monday Night | 72°F | Slight Chance Showers And Thunderstorms | 8 mph SSW | 25% |
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 Aug 4, 2026.