Idaho Falls (46 mi W), Idaho climate: Climate normals at a NOAA weather station
Idaho Falls (46 mi W)'s normal year runs from 6°F January nights to 89°F July afternoons, with 8.2 inches of precipitation and 25 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.9°C, January lows of −15°C, July highs of 32°C, 208 mm of precipitation a year.
- NOAA stationIdaho Falls (46 mi W)
- Station IDUSW00094143
- Location43.53°N 112.94°W
- Elevation4,938 ft (1,505 m)
On October 14, the normal high in Idaho Falls (46 mi W) is 61°F and the normal low 28°F, and the chance of measurable rain or snow is 14%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Idaho Falls (46 mi W).
- Jan 28° 6°
- Feb 33° 10°
- Mar 46° 21°
- Apr 57° 28°
- May 67° 37°
- Jun 77° 44°
- Jul 89° 50°
- Aug 87° 48°
- Sep 76° 38°
- Oct 60° 27°
- Nov 42° 17°
- Dec 29° 7°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like at Idaho Falls (46 mi W) each month?
July is the warmest month, with normal highs of 89°F; January the coldest, with normal lows of 6°F. The most precipitation falls in May (1.29 in), the least in July (0.39 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 28°F | 6°F | 16.9°F | 0.66 | 7.2 | 7 | <1 | 31 | 9 h 20 min |
| February | 33°F | 10°F | 21.9°F | 0.50 | 4.4 | 5 | <1 | 28 | 10 h 30 min |
| March | 46°F | 21°F | 33.7°F | 0.60 | 1.9 | 6 | <1 | 29 | 11 h 50 min |
| April | 57°F | 28°F | 42.6°F | 0.88 | 1.0 | 7 | <1 | 21 | 13 h 20 min |
| May | 67°F | 37°F | 52.0°F | 1.29 | 0.0 | 9 | <1 | 9 | 14 h 40 min |
| June | 77°F | 44°F | 60.5°F | 0.84 | 0.0 | 6 | 3 | 2 | 15 h 20 min |
| July | 89°F | 50°F | 69.3°F | 0.39 | 0.0 | 3 | 16 | <1 | 15 h 10 min |
| August | 87°F | 48°F | 67.2°F | 0.44 | 0.0 | 4 | 13 | <1 | 14 h |
| September | 76°F | 38°F | 57.0°F | 0.66 | 0.0 | 4 | 1 | 7 | 12 h 30 min |
| October | 60°F | 27°F | 43.5°F | 0.72 | 0.4 | 5 | <1 | 22 | 11 h 10 min |
| November | 42°F | 17°F | 29.4°F | 0.49 | 2.3 | 5 | <1 | 29 | 9 h 40 min |
| December | 29°F | 7°F | 18.2°F | 0.70 | 7.6 | 7 | <1 | 31 | 9 h |
| Year (annual) | 58°F | 28°F | 42.7°F | 8.17 | 24.8 | 68 | 34 | 208 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | −2°C | −15°C | −8.4°C | 17 mm | 18 cm |
| February | 1°C | −12°C | −5.6°C | 13 mm | 11 cm |
| March | 8°C | −6°C | 0.9°C | 15 mm | 5 cm |
| April | 14°C | −2°C | 5.9°C | 22 mm | 3 cm |
| May | 20°C | 3°C | 11.1°C | 33 mm | 0 cm |
| June | 25°C | 6°C | 15.8°C | 21 mm | 0 cm |
| July | 32°C | 10°C | 20.7°C | 10 mm | 0 cm |
| August | 30°C | 9°C | 19.6°C | 11 mm | 0 cm |
| September | 24°C | 3°C | 13.9°C | 17 mm | 0 cm |
| October | 15°C | −3°C | 6.4°C | 18 mm | 1 cm |
| November | 6°C | −9°C | −1.4°C | 12 mm | 6 cm |
| December | −1°C | −14°C | −7.7°C | 18 mm | 19 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094143; annual normals. Wet days: 0.01 inch or more; 90°F days and freezing nights: NOAA's day counts. Daylight: sunrise to sunset on the 15th, computed from the latitude.
Which months are mildest at Idaho Falls (46 mi W)?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (4).
That is a measurement, not a recommendation: it counts the months whose normal afternoon high sits between 65°F and 85°F, where a light layer is enough by day.
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094143.
When is the last frost at Idaho Falls (46 mi W)?
In Idaho Falls (46 mi W), the last spring frost (32°F) comes after June 11 in half of years and after July 1 in one year in ten; the first autumn frost comes before September 6 in half of years and before August 24 in one year in ten.
Frost-free in half of yearsFrost in 1 to 9 years out of 10Frost most years
- Last spring frost, half of years after
- June 111 year in 10 after July 1; 9 in 10 after May 20
- First autumn frost, half of years before
- September 61 year in 10 before August 24; 9 in 10 before September 21
NOAA puts the median frost-free season at 89 days, and the season without a hard freeze (28°F) at 118 days.
A hard freeze (28°F) comes after May 23 in half of springs and before September 18 in half of autumns.
By the USDA's method, the average of each year's coldest night over 1991-2020, the station is in plant hardiness zone 4b: the coldest night of a typical year reaches −21°F (30 complete years).
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USW00094143; the station zone: ACIS daily lows, 1991-2020. A 10% date means one year in ten has a frost after it in spring or before it in autumn.
How hot and how cold does it get at Idaho Falls (46 mi W)?
In a normal year in Idaho Falls (46 mi W), 34 days a year reach 90°F (1 of them 100°F or more), 208 nights fall to 32°F or colder and 68 days bring measurable precipitation.
- Days at 90°F or more
- 34a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 208a normal year
- Days that stay below freezing
- 60high of 32°F or less
- Days with 0.01 inch of precipitation
- 68a normal year
- Days with 1 inch of snow or more
- 11a normal year
The highest temperature in this station's record (since 1952) is 105°F, on July 13, 2002; the lowest is −47°F, on December 23, 1983.
The wettest calendar year on that record is 1963, with 14.40 in; the snowiest season is 2016–17, with 59.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USW00094143; records: ACIS (NOAA Regional Climate Centers), station USW00094143. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Idaho Falls (46 mi W)?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds at Idaho Falls (46 mi W), 4.5 kWh per square metre a day. July is the sunniest month (90%) and December the cloudiest (60%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 65% | 1.8 |
| February | 68% | 2.7 |
| March | 73% | 4.1 |
| April | 76% | 5.5 |
| May | 79% | 6.6 |
| June | 85% | 7.5 |
| July | 90% | 7.6 |
| August | 89% | 6.6 |
| September | 87% | 5.1 |
| October | 80% | 3.5 |
| November | 72% | 2.1 |
| December | 60% | 1.4 |
Source: NASA POWER solar climatology, 2001-2020 (CERES SYN1deg). Satellite-based, for the 1-degree cell (about 100 km across) around the station, so it describes the area rather than the airport.
How many heating and cooling degree days does Idaho Falls (46 mi W) record?
A normal year at Idaho Falls (46 mi W) brings 8,418 heating degree days, 57% more than the median U.S. place (5,373), and 315 cooling degree days, 65% fewer than the median (908). Eight months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,861 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,491 | 0 |
| February | 1,208 | 0 |
| March | 970 | 0 |
| April | 671 | 0 |
| May | 405 | 2 |
| June | 169 | 33 |
| July | 26 | 160 |
| August | 42 | 110 |
| September | 250 | 10 |
| October | 668 | 0 |
| November | 1,068 | 0 |
| December | 1,449 | 0 |
| Year (annual) | 8,418 | 315 |
Source: NOAA NCEI 1991-2020 monthly normals, station USW00094143. A degree day is one degree of a day's mean temperature below 65°F (heating) or above it (cooling); utilities use them to estimate energy use.
Have recent years at Idaho Falls (46 mi W) been warmer than normal?
2025 averaged 45.7°F, 3.0°F above the 1991-2020 normal of 42.7°F. 3 of the 3 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 44.8°F | +2.1°F | 6.51 | 18.0 |
| 2024 | 45.1°F | +2.4°F | 7.60 | 42.0 |
| 2025 | 45.7°F | +3.0°F | 7.69 | 19.5 |
Over 66 complete years from 1955 to 2025, the station's annual mean temperature rose at a fitted 3.7°F per century (+0.20°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USW00094143; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Idaho Falls (46 mi W)'s climate compare?
Idaho Falls (46 mi W) is warmer than 14 of the 85 places with their own NOAA record in Idaho, and wetter than 3. Across the 7,247 U.S. stations with normals, its annual mean of 42.7°F is warmer than 11%.
In the Köppen classification computed from these normals, Idaho Falls (46 mi W) is BSk: cold semi-arid steppe. What the classes mean.
Places with the most similar year elsewhere
Measured month by month on the normal high, low and precipitation, among places of 20,000 or more people in other states:
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers. Similarity: the root-mean-square difference of the 36 monthly figures, precipitation weighted so an inch counts like 6°F.
Questions about Idaho Falls (46 mi W)'s climate
What is the coldest month at Idaho Falls (46 mi W)?
January, with a normal high of 28°F and a normal low of 6°F. The warmest is July (89°F by day, 50°F at night).
Does it snow at Idaho Falls (46 mi W)?
Yes: 25 inches in a normal year, falling on 21 days with 0.1 inch or more, the most in December (7.6 inches).
What is the rainiest month at Idaho Falls (46 mi W)?
May, with 1.29 in of precipitation in a normal year; the driest is July with 0.39 in.
What plant hardiness zone is Idaho Falls (46 mi W) in?
By the same method at the station, the coldest night of a typical year reaches −21°F (30 years, 1991-2020): zone 4b.
How late can frost come at Idaho Falls (46 mi W)?
In half of years the last 32°F night comes after June 11; in one year in ten it comes after July 1. Waiting until July 1 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Howe, ID17 miles from this station, 44.0°F a year
- Arco, ID19 miles from this station, 43.7°F a year
- Craters Of The Moon, ID31 miles from this station, 39.1°F a year
- Blackfoot, ID38 miles from this station, 47.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made