Idaho Falls, ID Climate & Monthly Averages
Idaho Falls has a semi-arid climate. July is the hottest month, averaging 90° by day; January is the coldest at 31°.
Winter sets the pace in Idaho Falls
Idaho Falls spends most of the year cold. July, the warmest month, averages 90°F (32°C) by day - a figure many cities in our dataset pass in early spring - while January holds at 31°F (-1°C) with 84 wet days a year across the whole calendar.
July
90° by day 60° at nightJanuary
31° by day 15° at nightThe cold-weather pattern in numbers
2 months average under 20 mm of rain, the longest unbroken stretch running July through August. At its warmest, in July, Idaho Falls runs to 90°F (32°C) in the afternoon and back to 60°F (16°C) by dawn. January sits at the other end of the year: 31°F (-1°C) by day, 15°F (-9°C) at night. Across the gridded 2015-2024 daily record, the highest daily maximum for this location was 103°F (39°C) and the lowest daily minimum -21°F (-29°C).
Overnight lows average at or below freezing for 5 months, November through March.
Between the average July and the average January lie 30°C, a wider spread than 96% of the 3496 cities in our dataset. Sunshine averages 9.9 hours a day over the year, peaking in July at 14.2 hours. Days and nights are about 12°C apart on average - wider than 93% of the 3496 cities in our dataset.
More climate facts for Idaho Falls
- Hottest month: July - highs near 90°F (32°C)
- Coldest month: January - highs near 31°F (-1°C)
- Decade extremes (2015-2024): 103°F (39°C) high · -21°F (-29°C) low
- Wettest month: May (10 rainy days) · Sunniest: July (14.2 h sun/day)
- Climate type: semi-arid
- Annual swing: 30°C between the average warmest and coolest month · day to night: 12°C
- Snow: about 30 days a year
- Months averaging 30°C or hotter: 2
- Average humidity: 54%
From snow season to the warmest stretch in Idaho Falls
Spring (March through May)
Through spring, Idaho Falls is crisp but comfortable: 57°F (14°C) by day, 34°F (1°C) after dark, and expect showers on roughly 28 days across the season, plus about 6 snowy days. Daylight is generous - around 10.6 hours of sun a day.
Summer (June through August)
Summer runs hot here - highs near 85°F (30°C), nights near 57°F (14°C), and rain comes on about 9 days over the three months. Daylight is generous - around 13.4 hours of sun a day.
Fall (September through November)
Fall in Idaho Falls is crisp but comfortable, with daytime highs averaging 59°F (15°C) and nights around 37°F (3°C); expect showers on roughly 20 days across the season, plus about 5 snowy days.
Winter (December through February)
Winter runs to hard cold here - highs near 33°F (1°C), nights near 17°F (-8°C), and expect showers on roughly 27 days across the season, plus about 19 snowy days. Wind sharpens cold like this considerably; pair the forecast winds with the wind speed converter to judge exposed conditions.
The coldest and warmest values in the dataset
Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ. Need another precipitation unit? Use the rainfall converter.
Planning around winter in Idaho Falls
The easier weather window
The best time to visit Idaho Falls is generally May to June and September to October, when temperatures sit either side of the peak heat rather than in it. Daytime temperatures in that window sit near 71°F (21°C), with rain on about 7 days a month. For the same question asked the other way round, see where else is warm in May.
Cold-weather packing
Pack for Idaho Falls with lightweight, breathable clothing and serious sun protection and a heavy insulated coat, hat and gloves for winter. Note the gap between afternoon and night: July pairs 90°F (32°C) with 60°F (16°C).
Monthly highs, lows and seasonal change
| Month | High | Low | Rain days | Precipitation | Sunshine | Daylight | Wet-day chance | Humidity |
|---|---|---|---|---|---|---|---|---|
| January | 31° | 15° | 9 | 1.2 in | 6.1 h/day | 9.3 h | 28% | 77% |
| February | 36° | 19° | 9 | 1.2 in | 7.4 h/day | 10.4 h | 33% | 70% |
| March | 47° | 26° | 9 | 1.5 in | 9.1 h/day | 11.8 h | 30% | 62% |
| April | 57° | 33° | 9 | 1.3 in | 10.6 h/day | 13.4 h | 30% | 51% |
| May | 67° | 42° | 10 | 1.9 in | 12.1 h/day | 14.7 h | 32% | 49% |
| June | 80° | 52° | 5 | 0.8 in | 13.7 h/day | 15.4 h | 17% | 39% |
| July | 90° | 60° | 1 | 0.2 in | 14.2 h/day | 15.1 h | 4% | 29% |
| August | 86° | 58° | 3 | 0.5 in | 12.4 h/day | 14.0 h | 10% | 34% |
| September | 76° | 49° | 5 | 1.2 in | 11.0 h/day | 12.4 h | 15% | 42% |
| October | 59° | 37° | 7 | 1.4 in | 9.1 h/day | 10.9 h | 23% | 56% |
| November | 43° | 25° | 8 | 1.2 in | 7.1 h/day | 9.6 h | 27% | 67% |
| December | 32° | 17° | 9 | 1.4 in | 5.5 h/day | 9.0 h | 30% | 74% |
The route from winter to summer, month by month
Each card shows the average high and low. The bar places that month between Idaho Falls's coldest night and warmest afternoon.
January
- Rain
- 9 days
- Sunshine
- 6.1 h
- Daylight
- 9.3 h
- Snow
- 7 days
February
- Rain
- 9 days
- Sunshine
- 7.4 h
- Daylight
- 10.4 h
- Snow
- 5 days
March
- Rain
- 9 days
- Sunshine
- 9.1 h
- Daylight
- 11.8 h
- Snow
- 4 days
April
- Rain
- 9 days
- Sunshine
- 10.6 h
- Daylight
- 13.4 h
- Snow
- 2 days
May
- Rain
- 10 days
- Sunshine
- 12.1 h
- Daylight
- 14.7 h
June
- Rain
- 5 days
- Sunshine
- 13.7 h
- Daylight
- 15.4 h
July
- Rain
- 1 day
- Sunshine
- 14.2 h
- Daylight
- 15.1 h
August
- Rain
- 3 days
- Sunshine
- 12.4 h
- Daylight
- 14.0 h
September
- Rain
- 5 days
- Sunshine
- 11.0 h
- Daylight
- 12.4 h
October
- Rain
- 7 days
- Sunshine
- 9.1 h
- Daylight
- 10.9 h
- Snow
- 1 day
November
- Rain
- 8 days
- Sunshine
- 7.1 h
- Daylight
- 9.6 h
- Snow
- 4 days
December
- Rain
- 9 days
- Sunshine
- 5.5 h
- Daylight
- 9.0 h
- Snow
- 7 days
Looking for warmer alternatives? Browse warm places by month, or compare Idaho Falls's coolest part of the year: January, December, February.
Where Idaho Falls sits among other climates
- Idaho Falls averages 47°F (8°C) across the year - cooler than all but 5% of the 3496 cities we track.
- Annual precipitation is 13.9 inches (353 mm) - drier than all but 9% of the 3496 cities we track.
- Relative humidity averages 54% - drier than all but 9% of the 3496 cities we track.
These comparisons use the same ten-year window for every city in the dataset.