Irwin, ID Weather & Growing Conditions
Local forecast, frost dates, hardiness zone and planting guidance for Irwin, a city in Bonneville County, Idaho.
Tonight
45°F
Chance Showers And Thunderstorms then Showers And Thunderstorms Likely
A chance of showers and thunderstorms before midnight, then showers and thunderstorms likely. Mostly cloudy. Low around 45, with temperatures rising to around 48 overnight. South southeast wind around 3 mph. Chance of precipitation is 60%.
7-day forecast for Irwin
| When | Temp | Forecast | Wind | Precip |
|---|---|---|---|---|
| Tonight | 45°F | Chance Showers And Thunderstorms then Showers And Thunderstorms Likely | 3 mph SSE | 57% |
| Saturday | 63°F | Showers And Thunderstorms Likely then Chance Showers And Thunderstorms | 5 mph S | 61% |
| Saturday Night | 41°F | Chance Showers And Thunderstorms then Mostly Cloudy | 2 mph NW | 31% |
| Sunday | 67°F | Partly Sunny | 0 to 5 mph SW | 7% |
| Sunday Night | 42°F | Mostly Clear | 6 mph ENE | 0% |
| Monday | 75°F | Sunny | 2 to 10 mph S | 0% |
| Monday Night | 45°F | Partly Cloudy | 2 to 7 mph E | 0% |
| Tuesday | 77°F | Mostly Sunny | 2 to 12 mph S | 3% |
| Tuesday Night | 47°F | Partly Cloudy | 2 to 7 mph SE | 12% |
| Wednesday | 77°F | Sunny | 3 to 12 mph S | 11% |
| Wednesday Night | 46°F | Mostly Clear | 3 to 9 mph ESE | 6% |
| Thursday | 79°F | Sunny | 3 to 12 mph S | 6% |
| Thursday Night | 48°F | Partly Cloudy | 2 to 13 mph S | 3% |
| Friday | 79°F | Mostly Sunny | 5 to 15 mph SSE | 5% |
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 Sep 19, 2026.