Decatur, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Decatur, a city in Decatur County, Iowa.
Tonight
47°F
Chance Rain Showers then Cloudy
A chance of rain showers before 9pm. Cloudy, with a low around 47. West wind 10 to 14 mph, with gusts as high as 21 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Decatur
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 47°F | Chance Rain Showers then Cloudy | 10 to 14 mph W | 50% |
| Wednesday | 52°F | Mostly Cloudy | 15 mph W | 10% |
| Wednesday Night | 43°F | Mostly Cloudy | 10 mph W | 4% |
| Thursday | 53°F | Mostly Cloudy then Chance Rain Showers | 10 mph WNW | 30% |
| Thursday Night | 41°F | Mostly Cloudy | 8 mph NNW | 10% |
| Friday | 52°F | Partly Sunny | 5 to 8 mph N | 5% |
| Friday Night | 35°F | Mostly Cloudy | 3 mph NNW | 1% |
| Saturday | 56°F | Partly Sunny | 5 mph WSW | 3% |
| Saturday Night | 38°F | Mostly Clear | 5 mph W | 5% |
| Sunday | 61°F | Sunny | 7 mph W | 3% |
| Sunday Night | 40°F | Mostly Clear | 6 mph SW | 0% |
| Monday | 65°F | Sunny | 6 to 12 mph SW | 0% |
| Monday Night | 43°F | Mostly Clear | 6 mph WNW | 0% |
| Tuesday | 65°F | Mostly Sunny | 7 mph N | 0% |
Forecast source: National Weather Service (api.weather.gov) for Decatur (40.743, -93.833). Updated through the day.
Growing snapshot for Decatur
Last spring frost
Apr 16
First fall frost
Oct 21
Growing season
186 days
Hardiness zone
5b
More local growing data for Decatur: nearby ZIP 50067 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Lamoni Muni Ap, Ia (4.2 mi from Decatur). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.