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Idaho Falls Weather by Month
Average temperatures, rainfall and humidity for Idaho Falls, United States, month by month, built from OpenWeather’s historical records. Use it to see what a typical Idaho Falls month looks like before you travel — then check the live Idaho Falls forecast for the days ahead.
Warmest month
July
34°C average high
Coolest month
January
-4°C average low
Wettest month
May
62 mm of rain
Driest month
July
16 mm of rain
Average temperature and rainfall in Idaho Falls by month
Averages of the daily highs and lows recorded in each month, with total rainfall, mean humidity and mean wind speed.
| Month | Avg high | Avg low | Record low / high | Rainfall | Humidity | Wind |
|---|---|---|---|---|---|---|
| January | 3°C | -4°C | -25°C / 16°C | 26 mm | 76% | 10 km/h |
| February | 7°C | -2°C | -17°C / 19°C | 33 mm | 68% | 13 km/h |
| March | 12°C | 2°C | -17°C / 29°C | 39 mm | 60% | 14 km/h |
| April | 16°C | 5°C | -10°C / 28°C | 42 mm | 52% | 14 km/h |
| May | 22°C | 9°C | -8°C / 34°C | 62 mm | 47% | 13 km/h |
| June | 30°C | 15°C | 0°C / 39°C | 20 mm | 36% | 12 km/h |
| July | 34°C | 20°C | 6°C / 41°C | 16 mm | 33% | 12 km/h |
| August | 32°C | 18°C | 3°C / 40°C | 21 mm | 38% | 11 km/h |
| September | 27°C | 13°C | -2°C / 39°C | 36 mm | 44% | 12 km/h |
| October | 18°C | 6°C | -12°C / 31°C | 32 mm | 56% | 10 km/h |
| November | 10°C | 1°C | -20°C / 24°C | 28 mm | 65% | 10 km/h |
| December | 4°C | -3°C | -28°C / 18°C | 36 mm | 75% | 10 km/h |
Best time to visit Idaho Falls
The most comfortable time to visit Idaho Falls is generally May to June and September, balancing mild daytime temperatures against the driest stretch of the year. The city has strongly marked seasons and rain concentrates around May, totalling about 392 mm a year.
Travellers who prefer heat should aim for July, when highs average 34°C. May is the month to avoid if rain would spoil your plans — it averages 62 mm, roughly 4× the rainfall of the driest month (July).
Source: OpenWeather historical and statistical weather data. Values are long-term averages, not a forecast — see the Idaho Falls forecast for what is happening now.