Powell, Wyoming climate: Normal weather by month, frost dates and records
Powell's normal year runs from 6°F January nights to 85°F July afternoons, with 6.7 inches of precipitation and 11 inches of snow a year. (NOAA 1991-2020 normals)
In metric: a yearly mean of 6.2°C, January lows of −14°C, July highs of 30°C, 170 mm of precipitation a year.
- NOAA stationPowell Field Station
- Station IDUSC00487388
- Location44.78°N 108.76°W
- Elevation4,372 ft (1,333 m)
- Population6,551
On October 14, the normal high in Powell is 59°F and the normal low 30°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 Powell.
- Jan 32° 6°
- Feb 36° 10°
- Mar 48° 20°
- Apr 57° 28°
- May 66° 40°
- Jun 76° 47°
- Jul 85° 52°
- Aug 84° 50°
- Sep 73° 41°
- Oct 58° 29°
- Nov 43° 17°
- Dec 33° 8°
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 Powell each month?
July is the warmest month, with normal highs of 85°F; January the coldest, with normal lows of 6°F. The most precipitation falls in June (1.33 in), the least in December (0.10 in).
| Month | High | Low | Mean | Precip. | Snow | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|---|---|
| January | 32°F | 6°F | 18.8°F | 0.18 | 2.6 | 3 | <1 | 31 | 9 h 10 min |
| February | 36°F | 10°F | 23.0°F | 0.18 | 1.8 | 3 | <1 | 28 | 10 h 20 min |
| March | 48°F | 20°F | 33.9°F | 0.26 | 1.7 | 3 | <1 | 28 | 11 h 50 min |
| April | 57°F | 28°F | 42.6°F | 0.57 | 0.8 | 6 | <1 | 19 | 13 h 30 min |
| May | 66°F | 40°F | 52.8°F | 1.22 | 0.1 | 9 | <1 | 5 | 14 h 50 min |
| June | 76°F | 47°F | 61.6°F | 1.33 | 0.0 | 8 | 3 | <1 | 15 h 30 min |
| July | 85°F | 52°F | 68.8°F | 0.77 | 0.0 | 6 | 11 | <1 | 15 h 20 min |
| August | 84°F | 50°F | 66.7°F | 0.42 | 0.0 | 5 | 9 | <1 | 14 h 10 min |
| September | 73°F | 41°F | 56.9°F | 0.76 | 0.0 | 5 | 2 | 3 | 12 h 40 min |
| October | 58°F | 29°F | 43.4°F | 0.70 | 1.1 | 5 | <1 | 19 | 11 h |
| November | 43°F | 17°F | 30.0°F | 0.21 | 1.6 | 3 | <1 | 29 | 9 h 40 min |
| December | 33°F | 8°F | 20.4°F | 0.10 | 1.5 | 3 | <1 | 31 | 8 h 50 min |
| Year (annual) | 58°F | 29°F | 43.2°F | 6.70 | 11.2 | 57 | 24 | 191 |
The same normals in °C and millimetres
| Month | High | Low | Mean | Precip. | Snow |
|---|---|---|---|---|---|
| January | 0°C | −14°C | −7.3°C | 5 mm | 7 cm |
| February | 2°C | −12°C | −5.0°C | 5 mm | 5 cm |
| March | 9°C | −7°C | 1.1°C | 7 mm | 4 cm |
| April | 14°C | −2°C | 5.9°C | 14 mm | 2 cm |
| May | 19°C | 4°C | 11.6°C | 31 mm | 0 cm |
| June | 24°C | 8°C | 16.4°C | 34 mm | 0 cm |
| July | 30°C | 11°C | 20.4°C | 20 mm | 0 cm |
| August | 29°C | 10°C | 19.3°C | 11 mm | 0 cm |
| September | 23°C | 5°C | 13.8°C | 19 mm | 0 cm |
| October | 14°C | −2°C | 6.3°C | 18 mm | 3 cm |
| November | 6°C | −8°C | −1.1°C | 5 mm | 4 cm |
| December | 0°C | −13°C | −6.4°C | 3 mm | 4 cm |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00487388; 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 Powell?
Normal highs sit between 65°F and 85°F in May, June, August and September. Of those, August 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 USC00487388.
When is the last frost in Powell?
In Powell, the last spring frost (32°F) comes after May 19 in half of years and after June 4 in one year in ten; the first autumn frost comes before September 20 in half of years and before September 7 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 191 year in 10 after June 4; 9 in 10 after May 5
- First autumn frost, half of years before
- September 201 year in 10 before September 7; 9 in 10 before October 1
NOAA puts the median frost-free season at 123 days, and the season without a hard freeze (28°F) at 146 days.
A hard freeze (28°F) comes after May 5 in half of springs and before September 29 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Powell in zone 5a in ZIP code 82440, the nearest ZIP area. By the map's own method, the average of each year's coldest night over 1991-2020, Powell's NOAA station is in zone 5a: the coldest night of a typical year reaches −18°F (19 complete years).
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00487388; 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.
How hot and how cold does it get in Powell?
In a normal year in Powell, 24 days a year reach 90°F (1 of them 100°F or more), 191 nights fall to 32°F or colder and 57 days bring measurable precipitation.
- Days at 90°F or more
- 24a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 191a normal year
- Days that stay below freezing
- 47high of 32°F or less
- Days with 0.01 inch of precipitation
- 57a normal year
- Days with 1 inch of snow or more
- 6a normal year
The highest temperature in this station's record (since 1981) is 104°F, on June 10, 1988; the lowest is −34°F, on December 22, 1990.
The wettest calendar year on that record is 2019, with 10.02 in; the snowiest season is 1996–97, with 28.6 inches.
Source: NOAA NCEI 1991-2020 annual normals, station USC00487388; records: ACIS (NOAA Regional Climate Centers), station USC00487388. Records use complete months only; a month missing more than three days is left out.
How sunny is Powell?
Over a year 78% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Powell, 4.4 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (65%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 71% | 1.8 |
| February | 72% | 2.8 |
| March | 74% | 4.0 |
| April | 74% | 5.3 |
| May | 75% | 6.3 |
| June | 82% | 7.2 |
| July | 87% | 7.3 |
| August | 85% | 6.2 |
| September | 83% | 4.8 |
| October | 76% | 3.2 |
| November | 72% | 2.0 |
| December | 65% | 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 Powell need?
A normal year in Powell brings 8,227 heating degree days, 53% more than the median U.S. place (5,373), and 329 cooling degree days, 64% 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 1,934 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,432 | 0 |
| February | 1,176 | 0 |
| March | 963 | 0 |
| April | 671 | 0 |
| May | 386 | 6 |
| June | 149 | 45 |
| July | 34 | 152 |
| August | 55 | 108 |
| September | 260 | 17 |
| October | 670 | 0 |
| November | 1,049 | 0 |
| December | 1,383 | 0 |
| Year (annual) | 8,227 | 329 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00487388. 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 Powell been warmer than normal lately?
2021 averaged 45.4°F, 2.2°F above the 1991-2020 normal of 43.2°F.
| Year | Mean | Against normal | Precip. | Snow |
|---|---|---|---|---|
| 2021 | 45.4°F | +2.2°F | 3.82 | 22.2 |
Over 94 complete years from 1909 to 2021, the station's annual mean temperature rose at a fitted 1.5°F per century (+0.09°C per decade). A fitted rate summarizes the whole record; single years swing well above and below it.
Source: observed years: ACIS, station USC00487388; trend: NOAA GHCN-Monthly v4. A year counts only with all twelve months complete.
How does Powell's climate compare?
Powell is warmer than 25 of the other 70 places with their own NOAA record in Wyoming, and wetter than 3. Across the 7,247 U.S. stations with normals, its annual mean of 43.2°F is warmer than 13%.
In the Köppen classification computed from these normals, Powell 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.
Which places near Powell share this climate record?
Garland 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.
- Garland, WY135 people · 5 mi E
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 Powell's climate
What is the coldest month in Powell?
January, with a normal high of 32°F and a normal low of 6°F. The warmest is July (85°F by day, 52°F at night).
Does it snow in Powell?
Yes: 11 inches in a normal year, falling on 11 days with 0.1 inch or more, the most in January (2.6 inches).
What is the rainiest month in Powell?
June, with 1.33 in of precipitation in a normal year; the driest is December with 0.10 in.
What plant hardiness zone is Powell in?
The USDA's 2023 map puts Powell in zone 5a in ZIP code 82440, the nearest ZIP area. By the same method at Powell's NOAA station, the coldest night of a typical year reaches −18°F (19 years, 1991-2020): zone 5a.
How late can frost come in Powell?
In half of years the last 32°F night comes after May 19; in one year in ten it comes after June 4. Waiting until June 4 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Heart Mountain, WY11 miles from this station, 45.6°F a year
- Deaver, WY11 miles from this station, 46.1°F a year
- Lovell, WY18 miles from this station, 44.9°F a year
- Clark (3 mi NE), WY22 miles from this station, 44.6°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made