Harlan, IA Weather & Growing Conditions
Today
79°F
Chance Showers And Thunderstorms
A chance of showers and thunderstorms before 10am, then a chance of showers and thunderstorms between 10am and 11am, then a slight chance of showers and thunderstorms between 11am and noon, then a chance of showers and thunderstorms between noon and 2pm, then a slight chance of showers and thunderstorms between 2pm and 3pm, then a chance of showers and thunderstorms between 3pm and 4pm, then a chance of showers and thunderstorms. Partly sunny. High near 79, with temperatures falling to around 76 in the afternoon. North northwest wind 3 to 12 mph, with gusts as high as 17 mph. Chance of precipitation is 50%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Today | 79°F | Chance Showers And Thunderstorms | 3 to 12 mph NNW | 47% |
| Tonight | 58°F | Chance Showers And Thunderstorms then Patchy Smoke | 2 to 10 mph NNE | 88% |
| Wednesday | 72°F | Patchy Smoke | 3 to 7 mph ENE | 49% |
| Wednesday Night | 54°F | Mostly Clear | 0 to 6 mph ENE | 5% |
| Thursday | 80°F | Sunny | 0 to 5 mph ESE | 1% |
| Thursday Night | 60°F | Mostly Clear | 3 mph SE | 3% |
| Friday | 84°F | Sunny | 1 to 9 mph S | 3% |
| Friday Night | 66°F | Mostly Clear | 3 to 7 mph S | 8% |
| Saturday | 89°F | Sunny | 2 to 13 mph S | 3% |
| Saturday Night | 70°F | Mostly Clear | 9 to 13 mph S | 11% |
| Sunday | 90°F | Mostly Sunny | 8 to 13 mph SSE | 11% |
| Sunday Night | 70°F | Chance Showers And Thunderstorms | 13 mph SSE | 27% |
| Monday | 90°F | Chance Showers And Thunderstorms then Partly Sunny | 12 to 15 mph S | 25% |
| Monday Night | 70°F | Slight Chance Showers And Thunderstorms | 9 to 15 mph SE | 23% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Harlan, IA
Last spring frost
Apr 27
First fall frost
Oct 9
Growing season
165 days
Hardiness zone
5b
Explore more for Harlan, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Harlan, Ia (1.9 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Aug 4, 2026.