Mason City, IA Weather & Growing Conditions
Tonight
63°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely before midnight, then patchy fog and showers and thunderstorms likely between midnight and 1am, then patchy fog and showers and thunderstorms likely. Some of the storms could produce heavy rain. Cloudy. Low around 63, with temperatures rising to around 65 overnight. East southeast wind 7 to 12 mph, with gusts as high as 18 mph. Chance of precipitation is 70%. New rainfall amounts between 1 and 2 inches possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 63°F | Showers And Thunderstorms Likely | 7 to 12 mph ESE | 73% |
| Saturday | 72°F | Patchy Fog | 8 mph N | 53% |
| Saturday Night | 56°F | Slight Chance Rain Showers | 10 mph NNE | 22% |
| Sunday | 65°F | Slight Chance Rain Showers | 13 mph NE | 17% |
| Sunday Night | 50°F | Cloudy then Slight Chance Rain Showers | 10 mph ENE | 24% |
| Monday | 60°F | Chance Rain Showers | 12 mph ENE | 49% |
| Monday Night | 46°F | Chance Rain Showers | 6 to 9 mph ENE | 45% |
| Tuesday | 59°F | Slight Chance Rain Showers then Partly Sunny | 8 mph ENE | 16% |
| Tuesday Night | 43°F | Partly Cloudy | 5 mph E | 2% |
| Wednesday | 63°F | Sunny | 3 mph ESE | 0% |
| Wednesday Night | 48°F | Partly Cloudy | 2 mph SE | 5% |
| Thursday | 66°F | Slight Chance Rain Showers | 3 mph SSE | 16% |
| Thursday Night | 50°F | Partly Cloudy | 1 mph SSE | 8% |
| Friday | 67°F | Mostly Sunny | 1 to 5 mph SE | 8% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Mason City, IA
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5a
Explore more for Mason City, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Mason City, Ia (0.7 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Sep 19, 2026.