Irwin, ID
Climate overview — based on NOAA 1991-2020 normals from SWAN VALLEY, ID US.
Year-round temperatures (°F)
Climate summary
Irwin has an annual average temperature of 42.6°F with about 20.1 inches of precipitation per year. The warmest month is July (average high 84.9°F), and the coldest is January (average low 11.0°F). May is typically the wettest month (2.53 in) and July the driest (1.25 in).
Best time to visit Irwin
Full guide →Climate change signal
All-time records →122 of 366 (33.3%) of Irwin's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.
| 1960s | 28 | |
| 1970s | 26 | |
| 1980s | 60 | |
| 1990s | 58 | |
| 2000s | 54 | |
| 2010s | 39 | |
| 2020s | 101 |
Bars: number of all-time daily heat records still standing that were set in each decade.
Monthly averages
| Month | Avg High | Avg Low | Avg Temp | Precipitation | Snow | Rainy days |
|---|---|---|---|---|---|---|
| January | 30.4°F | 11.0°F | 20.7°F | 1.85 in | — | 10 |
| February | 34.7°F | 13.8°F | 24.2°F | 1.32 in | — | 9 |
| March | 45.0°F | 21.5°F | 33.3°F | 1.54 in | — | 10 |
| April | 56.1°F | 27.2°F | 41.6°F | 1.88 in | — | 12 |
| May | 65.9°F | 34.6°F | 50.3°F | 2.53 in | — | 13 |
| June | 74.9°F | 40.7°F | 57.8°F | 2.07 in | — | 10 |
| July | 84.9°F | 45.8°F | 65.3°F | 1.25 in | — | 8 |
| August | 84.2°F | 44.2°F | 64.2°F | 1.25 in | — | 8 |
| September | 74.5°F | 37.4°F | 55.9°F | 1.55 in | — | 8 |
| October | 59.3°F | 28.5°F | 43.9°F | 1.81 in | — | 8 |
| November | 43.0°F | 20.3°F | 31.6°F | 1.59 in | — | 9 |
| December | 31.6°F | 12.4°F | 22.0°F | 1.44 in | — | 9 |
Climate twins of Irwin
Why these? →The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).