Decatur, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Decatur, a city in Decatur County, Iowa.
Today
84°F
Partly Sunny
Partly sunny. High near 84, with temperatures falling to around 82 in the afternoon. West southwest wind 7 to 10 mph, with gusts as high as 21 mph. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Decatur
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 84°F | Partly Sunny | 7 to 10 mph WSW | 13% |
| Tonight | 64°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 2 to 7 mph N | 67% |
| Sunday | 68°F | Chance Rain Showers then Chance Showers And Thunderstorms | 8 to 12 mph NNE | 49% |
| Sunday Night | 58°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 10 mph NE | 63% |
| Monday | 61°F | Showers And Thunderstorms Likely | 12 mph NE | 63% |
| Monday Night | 52°F | Chance Rain Showers | 7 to 10 mph NE | 43% |
| Tuesday | 59°F | Mostly Cloudy | 9 mph NE | 11% |
| Tuesday Night | 47°F | Partly Cloudy | 3 to 7 mph NE | 5% |
| Wednesday | 63°F | Mostly Sunny | 6 mph ENE | 2% |
| Wednesday Night | 51°F | Partly Cloudy | 3 mph E | 6% |
| Thursday | 66°F | Slight Chance Rain Showers | 5 mph ESE | 17% |
| Thursday Night | 56°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph ESE | 20% |
| Friday | 68°F | Slight Chance Rain Showers | 6 mph E | 20% |
| Friday Night | 57°F | Mostly Cloudy | 5 mph ESE | 12% |
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 Sep 19, 2026.