Fort Hall, Idaho climate: Normal weather by month, frost dates and records
Fort Hall's normal year runs from 15°F January nights to 86°F July afternoons, with 10.5 inches of precipitation and 28 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.4°C, January lows of −9°C, July highs of 30°C, 266 mm of precipitation a year.
- NOAA stationFort Hall (1 mi NNE)
- Station IDUSC00103297
- Location43.04°N 112.41°W
- Elevation4,465 ft (1,361 m)
- From the center3 miles
- Population (census place)2,343
On October 22, the normal high in Fort Hall is 57°F and the normal low 29°F, and the chance of measurable rain or snow is 21%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Fort Hall.
- Jan 33° 15°
- Feb 38° 18°
- Mar 50° 26°
- Apr 58° 31°
- May 67° 39°
- Jun 76° 45°
- Jul 86° 51°
- Aug 86° 49°
- Sep 76° 41°
- Oct 60° 31°
- Nov 45° 22°
- Dec 33° 15°
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 Fort Hall each month?
July is the warmest month, with normal highs of 86°F; January the coldest, with normal lows of 15°F. The most precipitation falls in May (1.39 in), the least in July (0.44 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 33°F | 15°F | 23.8°F | 0.91 | 6.4 | 10 | <1 | 30 | 9 h 20 min |
| February | 38°F | 18°F | 27.7°F | 0.75 | 5.7 | 8 | <1 | 26 | 10 h 30 min |
| March | 50°F | 26°F | 37.6°F | 1.03 | 3.0 | 8 | <1 | 26 | 11 h 50 min |
| April | 58°F | 31°F | 44.5°F | 1.02 | 1.3 | 9 | <1 | 19 | 13 h 20 min |
| May | 67°F | 39°F | 53.2°F | 1.39 | 0.3 | 9 | <1 | 6 | 14 h 40 min |
| June | 76°F | 45°F | 60.5°F | 0.95 | 0.0 | 6 | 2 | 1 | 15 h 20 min |
| July | 86°F | 51°F | 68.5°F | 0.44 | 0.0 | 3 | 11 | <1 | 15 h |
| August | 86°F | 49°F | 67.4°F | 0.50 | 0.0 | 4 | 11 | <1 | 14 h |
| September | 76°F | 41°F | 58.4°F | 0.83 | 0.0 | 5 | 2 | 4 | 12 h 30 min |
| October | 60°F | 31°F | 45.7°F | 0.90 | 0.9 | 7 | <1 | 18 | 11 h 10 min |
| November | 45°F | 22°F | 33.4°F | 0.79 | 3.0 | 8 | <1 | 27 | 9 h 50 min |
| December | 33°F | 15°F | 23.9°F | 0.98 | 7.5 | 11 | <1 | 30 | 9 h |
| Year (annual) | 59°F | 32°F | 45.4°F | 10.49 | 28.1 | 88 | 26 | 186 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −9°C | −4.6°C | 23 mm | 16 cm |
| February | 3°C | −8°C | −2.4°C | 19 mm | 14 cm |
| March | 10°C | −4°C | 3.1°C | 26 mm | 8 cm |
| April | 15°C | −1°C | 6.9°C | 26 mm | 3 cm |
| May | 20°C | 4°C | 11.8°C | 35 mm | 1 cm |
| June | 24°C | 7°C | 15.8°C | 24 mm | 0 cm |
| July | 30°C | 10°C | 20.3°C | 11 mm | 0 cm |
| August | 30°C | 9°C | 19.7°C | 13 mm | 0 cm |
| September | 24°C | 5°C | 14.7°C | 21 mm | 0 cm |
| October | 16°C | 0°C | 7.6°C | 23 mm | 2 cm |
| November | 7°C | −5°C | 0.8°C | 20 mm | 8 cm |
| December | 0°C | −9°C | −4.5°C | 25 mm | 19 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00103297; 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 Fort Hall?
Normal highs sit between 65°F and 85°F in May, June and September. Of those, September has the fewest days with rain (5).
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 USC00103297.
When is the last frost in Fort Hall?
In Fort Hall, the last spring frost (32°F) comes after May 20 in half of years and after June 12 in one year in ten; the first autumn frost comes before September 20 in half of years and before September 1 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 201 year in 10 after June 12; 9 in 10 after May 6
- First autumn frost, half of years before
- September 201 year in 10 before September 1; 9 in 10 before October 7
NOAA puts the median frost-free season at 119 days, and the season without a hard freeze (28°F) at 149 days.
A hard freeze (28°F) comes after May 6 in half of springs and before October 4 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Fort Hall in zones 5b to 6a across its 2 ZIP code areas (6a in 83202, the largest). By the map's own method, the average of each year's coldest night over 1991-2020, Fort Hall's NOAA station is in zone 5b: the coldest night of a typical year reaches −12°F (24 complete years); the map interpolates between stations and terrain, so the station and the ZIP area can differ by half a zone.
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00103297; USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; 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.
What hardiness zone is each Fort Hall ZIP code in?
The USDA's 2023 map gives each ZIP code area one zone. Fort Hall's 2 ZIP code areas run from zone 5b to 6a: 1 in 5b and 1 in 6a. Each ZIP's frost dates are in the frost tool.
Source: USDA 2023 Plant Hardiness Zone Map, ZIP listings: PRISM Group, Oregon State University, https://prism.oregonstate.edu, accessed October 8, 2026; ZIP areas in the place: Census Bureau 2020 ZCTA-to-place relationship file. A ZIP area counts when at least a tenth of its land (and 0.5 km²) lies in the place.
How hot and how cold does it get in Fort Hall?
In a normal year in Fort Hall, 26 days a year reach 90°F (1 of them 100°F or more), 186 nights fall to 32°F or colder and 88 days bring measurable precipitation.
- Days at 90°F or more
- 26a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 186a normal year
- Days that stay below freezing
- 40high of 32°F or less
- Days with 0.01 inch of precipitation
- 88a normal year
- Days with 1 inch of snow or more
- 13a normal year
The highest temperature in this station's record (since 1914) is 104°F, on July 25, 1933; the lowest is −42°F, on February 9, 1933.
The wettest calendar year on that record is 1981, with 15.25 in; the snowiest season is 2003–04, with 53.0 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00103297; records: ACIS (NOAA Regional Climate Centers), station USC00103297. Records use complete months only; a month missing more than three days is left out.
How sunny is Fort Hall?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Fort Hall, 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 much heating and cooling does Fort Hall need?
A normal year in Fort Hall brings 7,403 heating degree days, 38% more than the median U.S. place (5,373), and 285 cooling degree days, 69% 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 1,917 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,277 | 0 |
| February | 1,044 | 0 |
| March | 850 | 0 |
| April | 615 | 0 |
| May | 368 | 2 |
| June | 161 | 24 |
| July | 26 | 134 |
| August | 35 | 110 |
| September | 212 | 15 |
| October | 597 | 0 |
| November | 947 | 0 |
| December | 1,272 | 0 |
| Year (annual) | 7,403 | 285 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00103297. 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.
Has Fort Hall been warmer than normal lately?
2025 averaged 47.8°F, 2.4°F above the 1991-2020 normal of 45.4°F. 2 of the 2 complete years since 2021 ran warmer than the normal.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 46.9°F | +1.5°F | 7.57 | 22.9 |
| 2025 | 47.8°F | +2.4°F | 12.08 | – |
Over 45 complete years from 1949 to 2025, the station's annual mean temperature rose at a fitted 4.4°F per century (+0.24°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00103297; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Fort Hall's climate compare?
Fort Hall is warmer than 32 of the other 84 places with their own NOAA record in Idaho, and wetter than 19. Across the 7,247 U.S. stations with normals, its annual mean of 45.4°F is warmer than 21%.
In the Köppen classification computed from these normals, Fort Hall 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 Fort Hall's climate
What is the coldest month in Fort Hall?
January, with a normal high of 33°F and a normal low of 15°F. The warmest is July (86°F by day, 51°F at night).
Does it snow in Fort Hall?
Yes: 28 inches in a normal year, falling on 25 days with 0.1 inch or more, the most in December (7.5 inches).
What is the rainiest month in Fort Hall?
May, with 1.39 in of precipitation in a normal year; the driest is July with 0.44 in.
What plant hardiness zone is Fort Hall in?
The USDA's 2023 map puts Fort Hall in zones 5b to 6a across its 2 ZIP code areas (6a in 83202, the largest). By the same method at Fort Hall's NOAA station, the coldest night of a typical year reaches −12°F (24 years, 1991-2020): zone 5b.
How late can frost come in Fort Hall?
In half of years the last 32°F night comes after May 20; in one year in ten it comes after June 12. Waiting until June 12 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Blackfoot, ID11 miles from this station, 47.2°F a year
- Pocatello, ID12 miles from this station, 47.0°F a year
- Aberdeen, ID22 miles from this station, 45.4°F a year
- American Falls, ID26 miles from this station, 48.7°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made