Thornton, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Thornton, a city in Cerro Gordo County, Iowa.
Today
49°F
Chance Rain Showers
A chance of rain showers. Cloudy. High near 49, with temperatures falling to around 47 in the afternoon. West northwest wind 14 to 17 mph, with gusts as high as 25 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Thornton
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 49°F | Chance Rain Showers | 14 to 17 mph WNW | 47% |
| Tonight | 41°F | Rain Showers Likely | 13 mph WNW | 65% |
| Thursday | 50°F | Chance Rain Showers then Cloudy | 10 to 15 mph NNW | 45% |
| Thursday Night | 33°F | Mostly Cloudy | 5 to 9 mph N | 10% |
| Friday | 47°F | Mostly Sunny | 2 to 6 mph NNE | 2% |
| Friday Night | 27°F | Partly Cloudy | 1 mph NNW | 0% |
| Saturday | 50°F | Mostly Sunny | 1 to 5 mph SW | 0% |
| Saturday Night | 33°F | Mostly Clear | 5 mph W | 2% |
| Sunday | 55°F | Sunny | 6 mph W | 2% |
| Sunday Night | 34°F | Mostly Clear | 5 mph SW | 0% |
| Monday | 61°F | Sunny | 5 to 10 mph SW | 0% |
| Monday Night | 37°F | Mostly Clear | 5 mph WNW | 0% |
| Tuesday | 59°F | Mostly Sunny | 3 mph NW | 0% |
| Tuesday Night | 38°F | Partly Cloudy | 2 mph SW | 1% |
Forecast source: National Weather Service (api.weather.gov) for Thornton (42.944, -93.387). Updated through the day.
Growing snapshot for Thornton
Last spring frost
May 3
First fall frost
Oct 1
Growing season
150 days
Hardiness zone
5a
More local growing data for Thornton: nearby ZIP 50479 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Mason City Muni Ap, Ia (15.3 mi from Thornton). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.