Irwin, ID Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Irwin, a city in Bonneville County, Idaho.
Tonight
34°F
Mostly Cloudy then Patchy Fog
Patchy fog after 5am. Mostly cloudy. Low around 34, with temperatures rising to around 36 overnight. East wind around 9 mph.
7-day forecast for Irwin
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 34°F | Mostly Cloudy then Patchy Fog | 9 mph E | 0% |
| Wednesday | 50°F | Areas Of Fog then Mostly Cloudy | 2 to 9 mph NW | 1% |
| Wednesday Night | 33°F | Areas Of Fog | 0 to 7 mph SE | 0% |
| Thursday | 47°F | Patchy Fog then Slight Chance Light Rain | 2 to 10 mph SSW | 22% |
| Thursday Night | 34°F | Slight Chance Rain And Snow then Areas Of Fog | 3 mph SSW | 22% |
| Friday | 46°F | Mostly Sunny | 1 to 6 mph SW | 4% |
| Friday Night | 33°F | Partly Cloudy | 1 to 5 mph SSE | 4% |
| Saturday | 53°F | Mostly Sunny | 0 to 9 mph SSW | 0% |
| Saturday Night | 35°F | Partly Cloudy | 0 to 14 mph ESE | 0% |
| Sunday | 58°F | Mostly Sunny | 3 to 20 mph S | 0% |
| Sunday Night | 37°F | Partly Cloudy | 3 to 10 mph SSE | 1% |
| Monday | 58°F | Mostly Sunny | 1 to 14 mph S | 2% |
| Monday Night | 38°F | Mostly Cloudy | 1 to 9 mph SSE | 4% |
| Tuesday | 56°F | Mostly Sunny | 1 to 9 mph SSW | 8% |
Forecast source: National Weather Service (api.weather.gov) for Irwin (43.403, -111.280). Updated through the day.
Growing snapshot for Irwin
Growing season
69 days
Hardiness zone
6a
More local growing data for Irwin: nearby ZIP 83449 weather · frost dates · planting calendar · Idaho frost dates
Nearby towns & communities
Climate data from the nearest NOAA station, Swan Valley, Id (4 mi from Irwin). Frost dates are 1991–2020 averages, not a forecast. Page updated Nov 4, 2026.