Decatur, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Decatur, a city in Decatur County, Iowa.
Today
88°F
Partly Sunny then Slight Chance Showers And Thunderstorms
A slight chance of showers and thunderstorms after 4pm. Partly sunny. High near 88, with temperatures falling to around 86 in the afternoon. South southwest wind around 6 mph. Chance of precipitation is 20%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast for Decatur
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 88°F | Partly Sunny then Slight Chance Showers And Thunderstorms | 6 mph SSW | 20% |
| Tonight | 65°F | Showers And Thunderstorms Likely | 6 to 9 mph NNE | 63% |
| Wednesday | 75°F | Showers And Thunderstorms Likely | 9 mph NE | 79% |
| Wednesday Night | 61°F | Chance Showers And Thunderstorms | 3 to 9 mph NE | 53% |
| Thursday | 82°F | Chance Showers And Thunderstorms then Mostly Sunny | 5 mph ENE | 29% |
| Thursday Night | 63°F | Mostly Clear | 3 mph E | 4% |
| Friday | 86°F | Sunny | 6 mph S | 6% |
| Friday Night | 67°F | Mostly Clear | 6 mph S | 12% |
| Saturday | 90°F | Sunny | 5 to 10 mph S | 4% |
| Saturday Night | 72°F | Mostly Clear | 12 mph S | 8% |
| Sunday | 92°F | Mostly Sunny | 10 to 14 mph SSW | 8% |
| Sunday Night | 72°F | Partly Cloudy | 10 to 14 mph SSW | 13% |
| Monday | 93°F | Mostly Sunny | 10 to 16 mph SSW | 13% |
| Monday Night | 73°F | Slight Chance Showers And Thunderstorms | 10 to 15 mph SSW | 23% |
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 Aug 4, 2026.