Mason City, IL Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Mason City, a city in Mason County, Illinois.
Today
60°F
Slight Chance Drizzle
A slight chance of drizzle. Cloudy, with a high near 60. West southwest wind around 14 mph, with gusts as high as 26 mph.
7-day forecast for Mason City
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 60°F | Slight Chance Drizzle | 14 mph WSW | 10% |
| Tonight | 43°F | Slight Chance Drizzle then Mostly Cloudy | 12 mph WSW | 10% |
| Thursday | 59°F | Mostly Cloudy then Slight Chance Light Rain | 10 to 14 mph W | 15% |
| Thursday Night | 42°F | Slight Chance Light Rain | 5 to 8 mph NW | 16% |
| Friday | 53°F | Partly Sunny | 12 mph N | 4% |
| Friday Night | 32°F | Partly Cloudy | 1 to 8 mph NNW | 0% |
| Saturday | 53°F | Sunny | 1 to 6 mph NW | 0% |
| Saturday Night | 32°F | Mostly Clear | 2 mph WNW | 1% |
| Sunday | 59°F | Sunny | 2 to 8 mph W | 1% |
| Sunday Night | 33°F | Clear | 1 to 5 mph WSW | 1% |
| Monday | 64°F | Sunny | 1 to 7 mph SW | 0% |
| Monday Night | 38°F | Mostly Clear | 5 mph SW | 0% |
| Tuesday | 66°F | Sunny | 5 mph WNW | 1% |
| Tuesday Night | 39°F | Mostly Clear | 2 mph NNE | 1% |
Forecast source: National Weather Service (api.weather.gov) for Mason City (40.202, -89.697). Updated through the day.
Growing snapshot for Mason City
Last spring frost
Apr 17
First fall frost
Oct 18
Growing season
182 days
Hardiness zone
6a
More local growing data for Mason City: nearby ZIP 62664 weather · frost dates · planting calendar · Illinois frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mason City 4Se, Il (5.1 mi from Mason City). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.