Duncan, IA Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Duncan, a community in Hancock County, Iowa.
Today
73°F
Showers And Thunderstorms Likely
Showers and thunderstorms likely. Mostly cloudy. High near 73, with temperatures falling to around 71 in the afternoon. Northwest wind 7 to 12 mph. Chance of precipitation is 60%. New rainfall amounts between a tenth and quarter of an inch possible.
7-day forecast for Duncan
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 73°F | Showers And Thunderstorms Likely | 7 to 12 mph NW | 60% |
| Tonight | 55°F | Chance Showers And Thunderstorms | 2 to 7 mph NNW | 53% |
| Wednesday | 74°F | Mostly Sunny | 3 mph NNE | 2% |
| Wednesday Night | 52°F | Mostly Clear | 2 mph SE | 1% |
| Thursday | 79°F | Sunny | 2 to 6 mph S | 1% |
| Thursday Night | 59°F | Mostly Clear | 7 mph S | 3% |
| Friday | 82°F | Sunny | 6 to 13 mph S | 10% |
| Friday Night | 64°F | Chance Showers And Thunderstorms | 7 to 12 mph S | 26% |
| Saturday | 85°F | Slight Chance Showers And Thunderstorms then Sunny | 6 to 14 mph S | 15% |
| Saturday Night | 67°F | Chance Showers And Thunderstorms | 10 to 14 mph NNW | 32% |
| Sunday | 85°F | Chance Showers And Thunderstorms then Mostly Sunny | 12 mph SE | 32% |
| Sunday Night | 66°F | Slight Chance Showers And Thunderstorms | 7 to 10 mph SE | 33% |
| Monday | 84°F | Chance Showers And Thunderstorms then Slight Chance Showers And Thunderstorms | 12 mph E | 33% |
| Monday Night | 66°F | Slight Chance Showers And Thunderstorms | 9 to 13 mph ENE | 35% |
Forecast source: National Weather Service (api.weather.gov) for Duncan (43.108, -93.702). Updated through the day.
Growing snapshot for Duncan
Last spring frost
Apr 29
First fall frost
Oct 7
Growing season
161 days
Hardiness zone
5a
More local growing data for Duncan: nearby ZIP 50438 weather · frost dates · planting calendar · Iowa frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Britt 3E, Ia (6.4 mi from Duncan). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.