Mountain Home, Idaho climate: Normal weather by month, frost dates and records
Mountain Home's normal year runs from 23°F December nights to 95°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 11.3°C, December lows of −5°C, July highs of 35°C.
- NOAA stationMountain Home
- Station IDUSC00106174
- Location43.13°N 115.71°W
- Elevation3,140 ft (957 m)
- Population16,912
On October 14, the normal high in Mountain Home is 68°F and the normal low 37°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Mountain Home.
- Jan 40° 23°
- Feb 47° 26°
- Mar 56° 30°
- Apr 63° 36°
- May 74° 45°
- Jun 84° 52°
- Jul 95° 60°
- Aug 93° 58°
- Sep 82° 48°
- Oct 67° 37°
- Nov 50° 28°
- Dec 39° 23°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
What is the weather like in Mountain Home each month?
July is the warmest month, with normal highs of 95°F; December the coldest, with normal lows of 23°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 40°F | 23°F | 31.7°F | – | <1 | 28 | 9 h 20 min |
| February | 47°F | 26°F | 36.2°F | – | <1 | 23 | 10 h 30 min |
| March | 56°F | 30°F | 43.0°F | – | <1 | 19 | 11 h 50 min |
| April | 63°F | 36°F | 49.4°F | – | <1 | 10 | 13 h 20 min |
| May | 74°F | 45°F | 59.1°F | – | 3 | 2 | 14 h 40 min |
| June | 84°F | 52°F | 68.0°F | – | 9 | <1 | 15 h 20 min |
| July | 95°F | 60°F | 77.3°F | – | 23 | <1 | 15 h 10 min |
| August | 93°F | 58°F | 75.4°F | – | 23 | <1 | 14 h |
| September | 82°F | 48°F | 64.9°F | – | 7 | 1 | 12 h 30 min |
| October | 67°F | 37°F | 51.9°F | – | <1 | 10 | 11 h 10 min |
| November | 50°F | 28°F | 39.3°F | – | <1 | 21 | 9 h 50 min |
| December | 39°F | 23°F | 31.2°F | – | <1 | 26 | 9 h |
| Year (annual) | 66°F | 39°F | 52.3°F | – | 65 | 139 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 4°C | −5°C | −0.2°C |
| February | 8°C | −3°C | 2.3°C |
| March | 13°C | −1°C | 6.1°C |
| April | 17°C | 2°C | 9.7°C |
| May | 23°C | 7°C | 15.1°C |
| June | 29°C | 11°C | 20.0°C |
| July | 35°C | 15°C | 25.2°C |
| August | 34°C | 14°C | 24.1°C |
| September | 28°C | 9°C | 18.3°C |
| October | 19°C | 3°C | 11.1°C |
| November | 10°C | −2°C | 4.1°C |
| December | 4°C | −5°C | −0.4°C |
NOAA publishes no 1991-2020 snowfall normal for this station, and no record within 25 miles keeps one, so snow is left out here rather than estimated.
Source: NOAA NCEI 1991-2020 monthly normals, station USC00106174; 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.
When is the best weather to visit Mountain Home?
Normal highs sit between 65°F and 85°F in May, June, September and October.
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 USC00106174.
When is the last frost in Mountain Home?
In Mountain Home, the last spring frost (32°F) comes after May 2 in half of years and after May 23 in one year in ten; the first autumn frost comes before October 8 in half of years and before September 25 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
- May 21 year in 10 after May 23; 9 in 10 after April 18
- First autumn frost, half of years before
- October 81 year in 10 before September 25; 9 in 10 before October 24
NOAA puts the median frost-free season at 157 days, and the season without a hard freeze (28°F) at 185 days.
A hard freeze (28°F) comes after April 18 in half of springs and before October 20 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Mountain Home in zone 7a in ZIP code 83648, the nearest ZIP area.
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00106174; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026. 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 in Mountain Home?
In a normal year in Mountain Home, 65 days a year reach 90°F (17 of them 100°F or more) and 139 nights fall to 32°F or colder.
- Days at 90°F or more
- 65a normal year
- Days at 100°F or more
- 17a normal year
- Nights at 32°F or colder
- 139a normal year
- Days that stay below freezing
- 14high of 32°F or less
The highest temperature in this station's record (since 1906) is 115°F, on July 13, 2002; the lowest is −36°F, on December 25, 1924.
The wettest calendar year on that record is 1970, with 18.99 in; the snowiest season is 1915–16, with 48.5 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00106174; records: ACIS (NOAA Regional Climate Centers), station USC00106174. Records use complete months only; a month missing more than three days is left out.
How sunny is Mountain Home?
Over a year 81% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Mountain Home, 4.6 kWh per square metre a day. July is the sunniest month (92%) and December the cloudiest (63%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 67% | 1.8 |
| February | 71% | 2.8 |
| March | 70% | 3.9 |
| April | 75% | 5.4 |
| May | 79% | 6.6 |
| June | 85% | 7.6 |
| July | 92% | 7.8 |
| August | 91% | 6.7 |
| September | 87% | 5.2 |
| October | 80% | 3.5 |
| November | 71% | 2.1 |
| December | 63% | 1.5 |
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 much heating and cooling does Mountain Home need?
A normal year in Mountain Home brings 5,623 heating degree days, 5% more than the median U.S. place (5,373), and 1,021 cooling degree days, 13% more than the median (908). Seven months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 3,171 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,032 | 0 |
| February | 805 | 0 |
| March | 681 | 0 |
| April | 472 | 3 |
| May | 223 | 42 |
| June | 63 | 153 |
| July | 5 | 386 |
| August | 12 | 334 |
| September | 100 | 98 |
| October | 412 | 6 |
| November | 772 | 0 |
| December | 1,046 | 0 |
| Year (annual) | 5,623 | 1,021 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00106174. 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.
How does Mountain Home's climate compare?
Mountain Home is warmer than 76 of the other 84 places with their own NOAA record in Idaho. Across the 7,247 U.S. stations with normals, its annual mean of 52.3°F is warmer than 51%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Which places near Mountain Home share this climate record?
Mountain Home AFB has no NOAA station with 1991-2020 normals of its own, and this station is the nearest full record. A place's own climate can differ from these figures, by several degrees where it sits much higher or lower than the station, nearer the coast, or inside a large city's heat; for the larger places the next nearest records are named with their yearly mean, so the spread around them is visible, and places of 50,000 or more have their own page with NOAA's gridded normals.
- Mountain Home AFB, ID3,198 people · 9 mi SW
Source: Census Bureau 2024 Gazetteer (place centers) and Vintage 2024 population estimates. Distance and direction from the station to each place's center.
Questions about Mountain Home's climate
What is the coldest month in Mountain Home?
December, with a normal high of 39°F and a normal low of 23°F. The warmest is July (95°F by day, 60°F at night).
What plant hardiness zone is Mountain Home in?
The USDA's 2023 map puts Mountain Home in zone 7a in ZIP code 83648, the nearest ZIP area.
How late can frost come in Mountain Home?
In half of years the last 32°F night comes after May 2; in one year in ten it comes after May 23. Waiting until May 23 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Bruneau, ID17 miles from this station, 55.2°F a year
- Glenns Ferry, ID24 miles from this station, 54.6°F a year
- Grand View, ID25 miles from this station, 53.0°F a year
- Boise Lucky Peak Dam, ID32 miles from this station, 52.8°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made