Powell, Idaho climate: Climate normals at a NOAA weather station
Powell's normal year runs from 18°F December nights to 83°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 5.9°C, December lows of −8°C, July highs of 28°C.
- NOAA stationPowell
- Station IDUSC00107320
- Location46.51°N 114.71°W
- Elevation3,530 ft (1,076 m)
On October 23, the normal high in Powell is 49°F and the normal low 29°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Powell.
- Jan 32° 18°
- Feb 37° 18°
- Mar 46° 24°
- Apr 53° 29°
- May 64° 35°
- Jun 71° 42°
- Jul 83° 46°
- Aug 82° 44°
- Sep 71° 37°
- Oct 54° 30°
- Nov 38° 24°
- Dec 30° 18°
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 Powell each month?
July is the warmest month, with normal highs of 83°F; December the coldest, with normal lows of 18°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 32°F | 18°F | 25.0°F | – | <1 | 31 | 9 h |
| February | 37°F | 18°F | 27.5°F | – | <1 | 28 | 10 h 20 min |
| March | 46°F | 24°F | 34.6°F | – | <1 | 30 | 11 h 50 min |
| April | 53°F | 29°F | 41.1°F | – | <1 | 25 | 13 h 30 min |
| May | 64°F | 35°F | 49.5°F | – | <1 | 12 | 15 h |
| June | 71°F | 42°F | 56.8°F | – | 1 | 2 | 15 h 50 min |
| July | 83°F | 46°F | 64.2°F | – | 7 | <1 | 15 h 30 min |
| August | 82°F | 44°F | 62.8°F | – | 8 | 1 | 14 h 20 min |
| September | 71°F | 37°F | 53.8°F | – | 1 | 10 | 12 h 40 min |
| October | 54°F | 30°F | 41.8°F | – | <1 | 22 | 11 h |
| November | 38°F | 24°F | 30.9°F | – | <1 | 28 | 9 h 30 min |
| December | 30°F | 18°F | 23.9°F | – | <1 | 31 | 8 h 40 min |
| Year (annual) | 55°F | 30°F | 42.7°F | – | 18 | 219 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 0°C | −8°C | −3.9°C |
| February | 3°C | −8°C | −2.5°C |
| March | 8°C | −5°C | 1.4°C |
| April | 12°C | −2°C | 5.1°C |
| May | 18°C | 2°C | 9.7°C |
| June | 22°C | 6°C | 13.8°C |
| July | 28°C | 8°C | 17.9°C |
| August | 28°C | 6°C | 17.1°C |
| September | 21°C | 3°C | 12.1°C |
| October | 12°C | −1°C | 5.4°C |
| November | 3°C | −4°C | −0.6°C |
| December | −1°C | −8°C | −4.5°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 USC00107320; 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 Powell?
Normal highs sit between 65°F and 85°F in June, July, August and September.
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 USC00107320.
When is the last frost at Powell?
In Powell, the last spring frost (32°F) comes after May 31 in half of years and after June 26 in one year in ten; the first autumn frost comes before September 12 in half of years and before August 28 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 311 year in 10 after June 26; 9 in 10 after May 14
- First autumn frost, half of years before
- September 121 year in 10 before August 28; 9 in 10 before October 1
NOAA puts the median frost-free season at 102 days, and the season without a hard freeze (28°F) at 141 days.
A hard freeze (28°F) comes after May 9 in half of springs and before September 30 in half of autumns.
Frost dates for every NOAA station in Idaho · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00107320. 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 Powell?
In a normal year in Powell, 18 days a year reach 90°F (1 of them 100°F or more) and 219 nights fall to 32°F or colder.
- Days at 90°F or more
- 18a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 219a normal year
- Days that stay below freezing
- 36high of 32°F or less
The highest temperature in this station's record (since 1962) is 105°F, on August 24, 1969; the lowest is −31°F, on December 22, 1990.
The wettest calendar year on that record is 1964, with 52.44 in; the snowiest season is 1971–72, with 337.3 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00107320; records: ACIS (NOAA Regional Climate Centers), station USC00107320. Records use complete months only; a month missing more than three days is left out.
How sunny is it at Powell?
Over a year 71% of the sunlight that would reach the ground under clear skies gets through the clouds at Powell, 3.8 kWh per square metre a day. July is the sunniest month (89%) and December the cloudiest (52%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 56% | 1.3 |
| February | 58% | 2.0 |
| March | 59% | 3.1 |
| April | 64% | 4.4 |
| May | 68% | 5.6 |
| June | 73% | 6.4 |
| July | 89% | 7.4 |
| August | 86% | 6.2 |
| September | 79% | 4.4 |
| October | 67% | 2.6 |
| November | 56% | 1.4 |
| December | 52% | 1.0 |
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 Powell record?
A normal year at Powell brings 8,242 heating degree days, 53% more than the median U.S. place (5,373), and 124 cooling degree days, 86% fewer than the median (908). Nine months need 300 or more heating degree days, a monthly mean of about 55°F or colder. For gardens and crops, NOAA counts 1,325 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,240 | 0 |
| February | 1,050 | 0 |
| March | 941 | 0 |
| April | 717 | 0 |
| May | 483 | 1 |
| June | 258 | 12 |
| July | 91 | 66 |
| August | 109 | 42 |
| September | 338 | 3 |
| October | 719 | 0 |
| November | 1,023 | 0 |
| December | 1,274 | 0 |
| Year (annual) | 8,242 | 124 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00107320. 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 Powell been warmer than normal?
2025 averaged 45.6°F, 2.9°F above the 1991-2020 normal of 42.7°F.
| Year | Mean | Against normal |
|---|---|---|
| 2025 | 45.6°F | +2.9°F |
Source: observed years: ACIS, station USC00107320. A year counts only with all twelve months complete.
How does Powell's climate compare?
Powell is warmer than 14 of the 85 places with their own NOAA record in Idaho. Across the 7,247 U.S. stations with normals, its annual mean of 42.7°F is warmer than 11%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Questions about Powell's climate
What is the coldest month at Powell?
December, with a normal high of 30°F and a normal low of 18°F. The warmest is July (83°F by day, 46°F at night).
How late can frost come at Powell?
In half of years the last 32°F night comes after May 31; in one year in ten it comes after June 26. Waiting until June 26 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Idaho climateThe statewide normals and every place in the state
- Stevensville, MT29 miles from this station, 45.6°F a year
- Hamilton, MT32 miles from this station, 44.8°F a year
- Western Agricultural Research Center, MT32 miles from this station, 45.7°F a year
- Alberton, MT36 miles from this station, 45.4°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made