Powder River, Wyoming climate: Normal weather by month, frost dates and records
Powder River's normal year runs from 11°F December nights to 88°F July afternoons. (NOAA 1991-2020 normals)
In metric: a yearly mean of 7.0°C, December lows of −12°C, July highs of 31°C.
- NOAA stationPowder River #2
- Station IDUSC00487376
- Location43.03°N 106.99°W
- Elevation5,700 ft (1,737 m)
- Population (census place)0
On October 22, the normal high in Powder River is 56°F and the normal low 28°F.
Normals describe a typical year at the station, not a forecast. The National Weather Service forecast for Powder River.
- Jan 34° 10°
- Feb 37° 13°
- Mar 49° 22°
- Apr 56° 29°
- May 66° 37°
- Jun 79° 46°
- Jul 88° 52°
- Aug 87° 51°
- Sep 75° 42°
- Oct 59° 31°
- Nov 44° 19°
- Dec 32° 11°
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 Powder River each month?
July is the warmest month, with normal highs of 88°F; December the coldest, with normal lows of 11°F.
| Month | High | Low | Mean | Wet days | 90°F days | Freezing nights | Daylight |
|---|---|---|---|---|---|---|---|
| January | 34°F | 10°F | 22.0°F | – | <1 | 30 | 9 h 20 min |
| February | 37°F | 13°F | 25.0°F | – | <1 | 28 | 10 h 30 min |
| March | 49°F | 22°F | 35.6°F | – | <1 | 27 | 11 h 50 min |
| April | 56°F | 29°F | 42.7°F | – | <1 | 21 | 13 h 20 min |
| May | 66°F | 37°F | 51.7°F | – | <1 | 7 | 14 h 40 min |
| June | 79°F | 46°F | 62.2°F | – | 3 | <1 | 15 h 20 min |
| July | 88°F | 52°F | 70.3°F | – | 16 | <1 | 15 h |
| August | 87°F | 51°F | 68.8°F | – | 13 | <1 | 14 h |
| September | 75°F | 42°F | 58.5°F | – | 1 | 4 | 12 h 30 min |
| October | 59°F | 31°F | 44.9°F | – | <1 | 21 | 11 h 10 min |
| November | 44°F | 19°F | 31.6°F | – | <1 | 27 | 9 h 50 min |
| December | 32°F | 11°F | 21.5°F | – | <1 | 30 | 9 h |
| Year (annual) | 59°F | 30°F | 44.6°F | – | 33 | 194 |
The same normals in °C and millimetres
| Month | High | Low | Mean |
|---|---|---|---|
| January | 1°C | −12°C | −5.6°C |
| February | 3°C | −10°C | −3.9°C |
| March | 9°C | −5°C | 2.0°C |
| April | 13°C | −2°C | 5.9°C |
| May | 19°C | 3°C | 10.9°C |
| June | 26°C | 8°C | 16.8°C |
| July | 31°C | 11°C | 21.3°C |
| August | 30°C | 11°C | 20.4°C |
| September | 24°C | 5°C | 14.7°C |
| October | 15°C | −1°C | 7.2°C |
| November | 7°C | −7°C | −0.2°C |
| December | 0°C | −12°C | −5.8°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 USC00487376; 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 Powder River?
Normal highs sit between 65°F and 85°F in May, June 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 USC00487376.
When is the last frost in Powder River?
In Powder River, the last spring frost (32°F) comes after May 23 in half of years and after June 5 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 231 year in 10 after June 5; 9 in 10 after May 9
- First autumn frost, half of years before
- September 201 year in 10 before September 7; 9 in 10 before October 4
NOAA puts the median frost-free season at 121 days, and the season without a hard freeze (28°F) at 143 days.
A hard freeze (28°F) comes after May 10 in half of springs and before October 1 in half of autumns.
The USDA's 2023 Plant Hardiness Zone Map puts Powder River in zone 5a in ZIP code 82648, the nearest ZIP area.
Frost dates for every NOAA station in Wyoming · Frost dates by ZIP code
Source: NOAA NCEI 1991-2020 annual normals (frost probabilities), station USC00487376; 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 Powder River?
In a normal year in Powder River, 33 days a year reach 90°F (1 of them 100°F or more) and 194 nights fall to 32°F or colder.
- Days at 90°F or more
- 33a normal year
- Days at 100°F or more
- 1a normal year
- Nights at 32°F or colder
- 194a normal year
- Days that stay below freezing
- 46high of 32°F or less
Source: NOAA NCEI 1991-2020 annual normals, station USC00487376.
How sunny is Powder River?
Over a year 79% of the sunlight that would reach the ground under clear skies gets through the clouds in the area around Powder River, 4.5 kWh per square metre a day. July is the sunniest month (87%) and December the cloudiest (70%).
| Month | Share of clear-sky sunshine | Sunshine, kWh/m² a day |
|---|---|---|
| January | 75% | 2.0 |
| February | 71% | 2.8 |
| March | 73% | 4.1 |
| April | 72% | 5.3 |
| May | 74% | 6.2 |
| June | 84% | 7.4 |
| July | 87% | 7.3 |
| August | 87% | 6.4 |
| September | 84% | 5.0 |
| October | 77% | 3.3 |
| November | 74% | 2.2 |
| December | 70% | 1.6 |
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 Powder River need?
A normal year in Powder River brings 7,827 heating degree days, 46% more than the median U.S. place (5,373), and 411 cooling degree days, 55% 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 2,082 growing degree days a year above 50°F.
| Month | Heating | Cooling |
|---|---|---|
| January | 1,335 | 0 |
| February | 1,118 | 0 |
| March | 913 | 0 |
| April | 669 | 0 |
| May | 413 | 3 |
| June | 133 | 47 |
| July | 22 | 184 |
| August | 31 | 149 |
| September | 221 | 28 |
| October | 623 | 0 |
| November | 1,001 | 0 |
| December | 1,348 | 0 |
| Year (annual) | 7,827 | 411 |
Source: NOAA NCEI 1991-2020 monthly normals, station USC00487376. 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 Powder River's climate compare?
Powder River is warmer than 36 of the other 70 places with their own NOAA record in Wyoming. Across the 7,247 U.S. stations with normals, its annual mean of 44.6°F is warmer than 18%.
Source: NOAA NCEI 1991-2020 normals for every station PlainClimate covers.
Questions about Powder River's climate
What is the coldest month in Powder River?
December, with a normal high of 32°F and a normal low of 11°F. The warmest is July (88°F by day, 52°F at night).
What plant hardiness zone is Powder River in?
The USDA's 2023 map puts Powder River in zone 5a in ZIP code 82648, the nearest ZIP area.
How late can frost come in Powder River?
In half of years the last 32°F night comes after May 23; in one year in ten it comes after June 5. Waiting until June 5 leaves about a one-in-ten chance of a later frost.
Nearby and next
- Wyoming climateThe statewide normals and every place in the state
- Powder River (School), WY0 miles from this station, 43.7°F a year
- Casper, WY28 miles from this station, 45.6°F a year
- Pathfinder Dam, WY40 miles from this station, 46.3°F a year
- Bates Creek #2, WY43 miles from this station, 44.0°F a year
- Compare two placesMonth by month, side by side
Download these normals (CSV) · JSON · How these figures are made