Irwin, IA Weather & Growing Conditions
Tonight
40°F
Rain Showers Likely
Rain showers likely. Cloudy. Low around 40, with temperatures rising to around 43 overnight. Northwest wind around 16 mph, with gusts as high as 25 mph. Chance of precipitation is 60%. New rainfall amounts less than a tenth of an inch possible.
7-day forecast
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 40°F | Rain Showers Likely | 16 mph NW | 57% |
| Wednesday | 49°F | Chance Rain Showers | 15 mph WNW | 40% |
| Wednesday Night | 38°F | Chance Rain Showers | 13 mph WNW | 27% |
| Thursday | 50°F | Chance Rain Showers then Mostly Cloudy | 12 mph NW | 28% |
| Thursday Night | 35°F | Mostly Cloudy | 2 to 8 mph N | 1% |
| Friday | 50°F | Mostly Sunny | 3 mph N | 1% |
| Friday Night | 30°F | Partly Cloudy | 0 mph | 0% |
| Saturday | 53°F | Mostly Sunny | 0 to 5 mph SW | 1% |
| Saturday Night | 34°F | Mostly Clear | 2 mph WSW | 0% |
| Sunday | 59°F | Sunny | 1 to 6 mph WSW | 0% |
| Sunday Night | 37°F | Mostly Clear | 5 mph SSW | 0% |
| Monday | 64°F | Sunny | 5 to 9 mph SW | 0% |
| Monday Night | 39°F | Mostly Clear | 0 to 3 mph WNW | 0% |
| Tuesday | 63°F | Mostly Sunny | 0 to 5 mph NNW | 0% |
Forecast source: National Weather Service (api.weather.gov). Updated through the day.
Growing snapshot for Irwin, IA
Last spring frost
Apr 27
First fall frost
Oct 9
Growing season
165 days
Hardiness zone
5a
Explore more for Irwin, IA: full frost dates · planting calendar · Iowa frost dates
Climate data from the nearest NOAA station, Harlan, Ia (11.6 mi). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.