Idaho Falls, ID Climate & Monthly Averages

Idaho, United States 🇺🇸 · semi-arid climate
Annual avg
47°
Hottest month
July
Coldest month
January
Rainy days / yr
84
Sunshine
9.9 h/day
Right now: 74° and sunny - see live conditions

The climate of Idaho Falls

Idaho Falls has a semi-arid climate, marked by big day-to-night temperature swings and modest rainfall. Average daytime highs range from about 31°F (-1°C) in January to around 90°F (32°C) in July, and the city records roughly 84 days of measurable precipitation a year.

Climate quick facts

  • Hottest month: July - highs near 90°F (32°C)
  • Coldest month: January - highs near 31°F (-1°C)
  • Record high: 103°F (39°C) · Record low: -21°F (-29°C) (2015–2024)
  • Wettest month: May (10 rainy days) · Sunniest: July (14.2 h sun/day)
  • Climate type: semi-arid - big day-to-night temperature swings and modest rainfall
  • Snow: about 30 days a year

Temperatures through the year

The warmest stretch of the year centers on July. Highs average 90°F (32°C) and overnight lows stay near 60°F (16°C). The coolest month is January, with typical highs of 31°F (-1°C) and lows around 15°F (-9°C). Based on 2015–2024 weather data, temperatures have reached as high as 103°F (39°C) and dropped as low as -21°F (-29°C).

Rain, sun and snow

May is usually the wettest month. It brings about 1.9 inches (48 mm) of rain over 10 days, while July is the driest. July brings the most sunshine, averaging 14.2 hours of sun a day. Snow falls on about 30 days in a typical year, mostly from October through April.

Monthly climate table

Monthly averages for Idaho Falls based on 2015–2024 weather data.
MonthHighLow Rain daysPrecipitation SunshineHumidity
January 31° 15° 9 1.2 in 6.1 h/day 77%
February 36° 19° 9 1.2 in 7.4 h/day 70%
March 47° 26° 9 1.5 in 9.1 h/day 62%
April 57° 33° 9 1.3 in 10.6 h/day 51%
May 67° 42° 10 1.9 in 12.1 h/day 49%
June 80° 52° 5 0.8 in 13.7 h/day 39%
July 90° 60° 1 0.2 in 14.2 h/day 29%
August 86° 58° 3 0.5 in 12.4 h/day 34%
September 76° 49° 5 1.2 in 11.0 h/day 42%
October 59° 37° 7 1.4 in 9.1 h/day 56%
November 43° 25° 8 1.2 in 7.1 h/day 67%
December 32° 17° 9 1.4 in 5.5 h/day 74%

Idaho Falls month by month

Idaho Falls weather in January

January brings highs around 31°F (-1°C), lows near 15°F (-9°C), about 9 wet days and roughly 7 snowy days - typically the coldest month of the year in Idaho Falls.

Idaho Falls weather in February

February brings highs around 36°F (2°C), lows near 19°F (-7°C), about 9 wet days and roughly 5 snowy days.

Idaho Falls weather in March

March brings highs around 47°F (8°C), lows near 26°F (-3°C), about 9 wet days and roughly 4 snowy days.

Idaho Falls weather in April

April brings highs around 57°F (14°C), lows near 33°F (0°C), about 9 wet days and roughly 2 snowy days.

Idaho Falls weather in May

May brings highs around 67°F (20°C), lows near 42°F (5°C), about 10 wet days - typically the wettest month of the year in Idaho Falls.

Idaho Falls weather in June

June brings highs around 80°F (27°C), lows near 52°F (11°C), about 5 wet days.

Idaho Falls weather in July

July brings highs around 90°F (32°C), lows near 60°F (16°C), about 1 wet days - typically the hottest month and the driest month and the sunniest month of the year in Idaho Falls.

Idaho Falls weather in August

August brings highs around 86°F (30°C), lows near 58°F (14°C), about 3 wet days.

Idaho Falls weather in September

September brings highs around 76°F (24°C), lows near 49°F (10°C), about 5 wet days.

Idaho Falls weather in October

October brings highs around 59°F (15°C), lows near 37°F (3°C), about 7 wet days and roughly 1 snowy days.

Idaho Falls weather in November

November brings highs around 43°F (6°C), lows near 25°F (-4°C), about 8 wet days and roughly 4 snowy days.

Idaho Falls weather in December

December brings highs around 32°F (0°C), lows near 17°F (-8°C), about 9 wet days and roughly 7 snowy days.

Seasons in Idaho Falls

Spring (March through May)

Spring in Idaho Falls stays on the cool side of mild, with daytime highs averaging 57°F (14°C) and nights around 34°F (1°C); expect showers on roughly 28 days across the season, plus around 6 snowy days.

Summer (June through August)

Summer in Idaho Falls brings hot afternoons, with daytime highs averaging 85°F (30°C) and nights around 57°F (14°C); rain falls on about 9 days over the three months.

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 around 5 snowy days.

Winter (December through February)

Winter in Idaho Falls is bitterly cold, with daytime highs averaging 33°F (1°C) and nights around 17°F (-8°C); expect showers on roughly 27 days across the season, plus around 19 snowy days. Wind makes those temperatures feel harsher than they sound - pair the forecast winds with the wind speed converter to judge conditions on exposed skin.

Climate questions, answered

What is the average temperature in Idaho Falls?
Averaged over all twelve months, Idaho Falls sits at 47°F (8°C) - about 59°F (15°C) by day and 36°F (2°C) after dark.
Is Idaho Falls hot in summer?
It gets properly warm: plan on 90°F (32°C) through July, with the occasional hotter spike.
Is Idaho Falls cold in winter?
Sub-freezing nights are routine - 15°F (-9°C) is the January average, so pack for winter proper.
How many rainy days does Idaho Falls get in a year?
About 84 days bring measurable precipitation, with May the wettest month and July the driest.

Best time to visit Idaho Falls

The best time to visit Idaho Falls is generally May to June and September to October, when temperatures are at their most comfortable before or after the peak heat. Daytime temperatures in that window typically sit near 71°F (21°C).

Pack for Idaho Falls with lightweight, breathable clothing and strong sun protection for the hot months; a heavy insulated coat, hat and gloves for winter. Evenings can feel noticeably cooler than afternoons - July nights average 60°F (16°C).

Idaho Falls temperature records (2015-2024)

Highest recorded
103°
in July
Lowest recorded
-21°
in January
Annual precipitation
13.9"
Snowy days / yr
30

Derived from ERA5 reanalysis data, 2015–2024. Official station records may differ.