Decatur, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Decatur, a city in Decatur County, Iowa.
Overnight
70°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms after 2am. Mostly cloudy. Low around 70, with temperatures rising to around 72 overnight. South wind around 9 mph. Chance of precipitation is 30%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Decatur
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Overnight | 70°F | Chance Showers And Thunderstorms | 9 mph S | 29% |
| Saturday | 84°F | Chance Showers And Thunderstorms | 9 mph SW | 33% |
| Saturday Night | 64°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 5 to 8 mph N | 70% |
| Sunday | 70°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 8 to 12 mph NNE | 60% |
| Sunday Night | 59°F | Showers And Thunderstorms Likely | 10 mph NE | 60% |
| Monday | 62°F | Rain Showers Likely | 10 mph NE | 56% |
| Monday Night | 53°F | Chance Rain Showers | 9 mph NE | 53% |
| Tuesday | 60°F | Mostly Cloudy | 9 mph NE | 11% |
| Tuesday Night | 48°F | Mostly Cloudy | 3 to 7 mph NE | 4% |
| Wednesday | 63°F | Mostly Sunny | 6 mph ENE | 2% |
| Wednesday Night | 52°F | Partly Cloudy | 3 mph E | 4% |
| Thursday | 65°F | Partly Sunny | 5 mph ESE | 13% |
| Thursday Night | 55°F | Mostly Cloudy then Slight Chance Rain Showers | 3 mph E | 16% |
| Friday | 67°F | Slight Chance Rain Showers | 2 to 6 mph E | 16% |
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.