Defiance, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Defiance, a city in Shelby County, Iowa.
Today
76°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 4pm, then a chance of showers and thunderstorms between 4pm and 5pm, then showers and thunderstorms likely. Mostly cloudy. High near 76, with temperatures falling to around 74 in the afternoon. North northeast wind 8 to 12 mph, with gusts as high as 18 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Defiance
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 76°F | Chance Showers And Thunderstorms | 8 to 12 mph NNE | 64% |
| Tonight | 57°F | Patchy Smoke | 2 to 9 mph NE | 82% |
| Wednesday | 72°F | Patchy Smoke | 2 to 6 mph ENE | 43% |
| Wednesday Night | 53°F | Mostly Clear | 0 to 5 mph E | 3% |
| Thursday | 79°F | Sunny | 0 to 5 mph ESE | 1% |
| Thursday Night | 60°F | Mostly Clear | 3 mph SSE | 2% |
| Friday | 84°F | Sunny | 2 to 8 mph S | 3% |
| Friday Night | 65°F | Mostly Clear | 7 mph S | 9% |
| Saturday | 88°F | Sunny | 3 to 12 mph S | 3% |
| Saturday Night | 69°F | Mostly Clear | 9 to 14 mph S | 13% |
| Sunday | 89°F | Mostly Sunny | 8 to 12 mph SSE | 13% |
| Sunday Night | 69°F | Chance Showers And Thunderstorms | 12 mph SSE | 26% |
| Monday | 88°F | Chance Showers And Thunderstorms then Partly Sunny | 10 to 14 mph S | 26% |
| Monday Night | 70°F | Partly Cloudy then Slight Chance Showers And Thunderstorms | 10 to 14 mph SE | 21% |
Forecast source: National Weather Service (api.weather.gov) for Defiance (41.825, -95.340). Updated through the day.
Growing snapshot for Defiance
Last spring frost
Apr 27
First fall frost
Oct 9
Growing season
165 days
Hardiness zone
5a
More local growing data for Defiance: nearby ZIP 51527 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Harlan, Ia (13.4 mi from Defiance). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.