Bruneau, Idaho climate: Normal weather by month, frost dates and records
Bruneau's normal year runs from 26°F December nights to 96°F July afternoons, with 7.4 inches of precipitation a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 12.9°C, December lows of −3°C, July highs of 35°C, 187 mm of precipitation a year.
- NOAA stationBruneau
- Station IDUSC00101195
- Location42.88°N 115.80°W
- Elevation2,530 ft (771 m)
- Population (census place)36
On October 22, the normal high in Bruneau is 66°F and the normal low 38°F, and the chance of measurable rain or snow is 13%.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Bruneau.
- Jan 43° 27°
- Feb 51° 29°
- Mar 61° 35°
- Apr 68° 40°
- May 76° 48°
- Jun 85° 55°
- Jul 96° 61°
- Aug 94° 58°
- Sep 84° 49°
- Oct 70° 40°
- Nov 54° 32°
- Dec 43° 26°
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 Bruneau each month?
July is the warmest month, with normal highs of 96°F; December the coldest, with normal lows of 26°F. The most precipitation falls in May (1.17 in), the least in August (0.13 in).
| Month | High | Low | Mean | Precip. | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|
| January | 43°F | 27°F | 35.1°F | 0.97 | 6 | <1 | 25 | 9 h 20 min |
| February | 51°F | 29°F | 40.1°F | 0.48 | 4 | <1 | 19 | 10 h 30 min |
| March | 61°F | 35°F | 47.9°F | 0.73 | 5 | <1 | 16 | 11 h 50 min |
| April | 68°F | 40°F | 54.3°F | 0.72 | 7 | <1 | 7 | 13 h 20 min |
| May | 76°F | 48°F | 61.9°F | 1.17 | 6 | 2 | 1 | 14 h 40 min |
| June | 85°F | 55°F | 69.9°F | 0.60 | 4 | 8 | <1 | 15 h 20 min |
| July | 96°F | 61°F | 78.1°F | 0.14 | 1 | 24 | <1 | 15 h |
| August | 94°F | 58°F | 76.3°F | 0.13 | 1 | 21 | <1 | 14 h |
| September | 84°F | 49°F | 66.6°F | 0.26 | 1 | 7 | 1 | 12 h 30 min |
| October | 70°F | 40°F | 54.6°F | 0.62 | 4 | <1 | 8 | 11 h 10 min |
| November | 54°F | 32°F | 43.0°F | 0.61 | 5 | <1 | 19 | 9 h 50 min |
| December | 43°F | 26°F | 34.7°F | 0.95 | 6 | <1 | 25 | 9 h |
| Year (annual) | 69°F | 42°F | 55.2°F | 7.38 | 51 | 63 | 121 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. |
|---|---|---|---|---|
| January | 6°C | −3°C | 1.7°C | 25 mm |
| February | 11°C | −2°C | 4.5°C | 12 mm |
| March | 16°C | 2°C | 8.8°C | 19 mm |
| April | 20°C | 5°C | 12.4°C | 18 mm |
| May | 24°C | 9°C | 16.6°C | 30 mm |
| June | 30°C | 13°C | 21.1°C | 15 mm |
| July | 35°C | 16°C | 25.6°C | 4 mm |
| August | 35°C | 15°C | 24.6°C | 3 mm |
| September | 29°C | 9°C | 19.2°C | 7 mm |
| October | 21°C | 4°C | 12.6°C | 16 mm |
| November | 12°C | 0°C | 6.1°C | 15 mm |
| December | 6°C | −3°C | 1.5°C | 24 mm |
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 USC00101195; 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 Bruneau?
Normal highs sit between 65°F and 85°F in April, May, September and October. Of those, September has the fewest days with rain (1).
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 USC00101195.
When is the last frost in Bruneau?
In Bruneau, the last spring frost (32°F) comes after April 17 in half of years and after May 7 in one year in ten; the first autumn frost comes before October 17 in half of years and before October 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
- April 171 year in 10 after May 7; 9 in 10 after March 31
- First autumn frost, half of years before
- October 171 year in 10 before October 1; 9 in 10 before November 1
NOAA puts the median frost-free season at 181 days, and the season without a hard freeze (28°F) at 213 days.
A hard freeze (28°F) comes after March 30 in half of springs and before October 31 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Bruneau in zone 7a in ZIP code 83604, 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 USC00101195; 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 Bruneau?
In a normal year in Bruneau, 63 days a year reach 90°F (11 of them 100°F or more), 121 nights fall to 32°F or colder and 51 days bring measurable precipitation.
- Days at 90°F or more
- 63a normal year
- Days at 100°F or more
- 11a normal year
- Nights at 32°F or colder
- 121a normal year
- Days that stay below freezing
- 10high of 32°F or less
- Days with 0.01 inch of precipitation
- 51a normal year
The highest temperature in this station's record (since 1937) is 113°F, on July 12, 2002; the lowest is −32°F, on December 22, 1990.
The wettest calendar year on that record is 1996, with 13.48 in; the snowiest season is 1968–69, with 15.7 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00101195; records: ACIS (NOAA Regional Climate Centers), station USC00101195. Records use complete months only; a month missing more than three days is left out.
How sunny is Bruneau?
Over a year 80% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Bruneau, 4.6 kWh per square metre a day. July is the sunniest month (90%) and December the cloudiest (62%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 66% | 1.9 |
| February | 68% | 2.7 |
| March | 72% | 4.1 |
| April | 76% | 5.5 |
| May | 79% | 6.7 |
| June | 86% | 7.6 |
| July | 90% | 7.6 |
| August | 89% | 6.6 |
| September | 88% | 5.3 |
| October | 82% | 3.6 |
| November | 73% | 2.2 |
| December | 62% | 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 Bruneau need?
A normal year in Bruneau brings 4,669 heating degree days, 13% fewer than the median U.S. place (5,373), and 1,127 cooling degree days, 24% 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 3,580 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 928 | 0 |
| February | 699 | 0 |
| March | 530 | 0 |
| April | 328 | 5 |
| May | 152 | 57 |
| June | 31 | 179 |
| July | 1 | 409 |
| August | 4 | 354 |
| September | 67 | 114 |
| October | 332 | 8 |
| November | 660 | 0 |
| December | 939 | 0 |
| Year (annual) | 4,669 | 1,127 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00101195. 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 Bruneau's climate compare?
Bruneau is warmer than 84 of the other 84 places with their own NOAA record in Idaho, and wetter than 2. Across the 7,247 U.S. stations with normals, its annual mean of 55.2°F is warmer than 61%.
In the Köppen classification computed from these normals, Bruneau is BWk: cold desert. 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 Bruneau's climate
What is the coldest month in Bruneau?
December, with a normal high of 43°F and a normal low of 26°F. The warmest is July (96°F by day, 61°F at night).
What is the rainiest month in Bruneau?
May, with 1.17 in of precipitation in a normal year; the driest is August with 0.13 in.
What plant hardiness zone is Bruneau in?
The USDA's 2023 map puts Bruneau in zone 7a in ZIP code 83604, the nearest ZIP area.
How late can frost come in Bruneau?
In half of years the last 32°F night comes after April 17; in one year in ten it comes after May 7. Waiting until May 7 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Mountain Home, ID17 miles from this station, 52.3°F a year
- Grand View, ID21 miles from this station, 53.0°F a year
- Glenns Ferry, ID25 miles from this station, 54.6°F a year
- Swan Falls Powerhouse, ID39 miles from this station, 55.2°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made