Chicago and Northwestern Railroad Depot · Photo: Jon Roanhaus · CC BY-SA 4.0Hardly any U.S. towns collect less precipitation than Powder River: 10 inches a year
Expect July afternoons of about 88°. In January, nights here are colder than in 91% of U.S. towns. Decade by decade the climate has edged up, 1.6° above 1901–2000. Tender plants can go out after about May 30; in half of years the first frost comes by September 22.
A year in Powder River at a glance
Each month’s typical high and low, and what it brings.
What stands out about Powder River’s climate
Compared with towns across the U.S., with Powder River’s place in Wyoming beside it.
What a year in Powder River feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 115 frost-free days a year
In half of years the last 32° night comes by May 30 and the first by September 22. Frost and day counts come from NOAA’s station at Powder Rvr (school), WY, 1.2 miles from the town’s center, at about the same height.
The 2023 USDA map puts Powder River’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −19°. Plant labels use the zone; frost dates tell you when to plant.
Freezing nights by month
Average nights at or below 32°
90° days by month
Average days at 90° or more
About 10 inches of rain a year
May is the wettest month and January the driest.
Rain + melted snow by month
Inches of water
Heating and cooling a home in Powder River
96% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from October through May.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Powder Rvr (school), WY.
Living with Powder River’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
115 frost-free days in zone 5a. The last frost comes by May 30 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Sep 22.
Months with highs of 62–84° and lows of 40° or more: June and September. 13 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Powder River from natural hazards, river flooding is the largest share (43%); heat waves, cold waves, winter storms and ice storms together are 8%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Powder River and similar climates
TownRatings has no climate map of the towns around Powder River yet.
Temperatures and precipitation come from NOAA’s 5 km grid; snow and day counts from the stations named on this page.
Warmer than it used to be
The last 30 years in Powder River averaged 1.6° warmer than the 1900s. The biggest change is in March (+4.0°).
A bigger shift than in 66% of U.S. towns.
Change by month
The two periods overlap (1991–2000 is in both), which makes the gap a little smaller than it would be between separate periods.
How Powder River compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Powder River’s place among Wyoming’s.
Powder River weather by month
Highs, lows and precipitation from NOAA’s grid at Powder River’s center. 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 35° | 12° | 0.3" | 14° – 32° |
| February | 37° | 14° | 0.4" | 14° – 33° |
| March | 48° | 23° | 0.6" | 27° – 43° |
| April | 56° | 29° | 1.1" | 36° – 47° |
| May | 66° | 38° | 2.0" | 46° – 58° |
| June | 79° | 46° | 1.2" | 57° – 68° |
| July | 88° | 53° | 0.9" | 62° – 75° |
| August | 86° | 51° | 0.5" | 63° – 73° |
| September | 75° | 42° | 0.8" | 53° – 64° |
| October | 59° | 30° | 1.0" | 36° – 52° |
| November | 45° | 20° | 0.5" | 19° – 43° |
| December | 34° | 12° | 0.3" | 15° – 29° |
| Year | 59° | 31° | 9.7" |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 19° to 43°. August is the most reliable, staying within 9°.
Where Powder River’s numbers come from
Normals are 30-year averages, not a forecast. How TownRatings reads climate data →
- Temperatures and precipitation: NOAA’s gridded 1991–2020 normals for the 5 km cell at Powder River’s center.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Powder Rvr (school), WY, 1.2 miles from the town’s center, at about the same height; the nearest station that passes our checks for distance, height and agreement with the grid.
- Growing zone: USDA Plant Hardiness Zone Map, 2023. USDA Agricultural Research Service and PRISM Group, Oregon State University, prism.oregonstate.edu/phzm, accessed 8 Oct 2026.
- Then and now: NOAA’s gridded normals for 1901–2000 at the same cell.
- Storms and extremes: FEMA National Risk Index (expected annual losses to buildings).
Common questions about Powder River’s climate
What is the weather like in Powder River?
A typical July afternoon reaches 88°, a January night drops to 12°. Colder January nights than 91% of U.S. towns; hotter July afternoons than 67% of U.S. towns.
How cold does it get in Powder River in winter?
December nights average 12°. About 200 nights a year reach 32° or below and 21 reach 0° or below. In the coldest December of the last 30 years the month averaged 15°.
How hot does it get in Powder River?
July, with a typical high of 88° and a low of 53°. About 31 days a year reach 90° (Powder Rvr (school), WY).
When is the first and last frost in Powder River?
In half of years the last spring frost (32°) comes by May 30 and the first fall frost by September 22, about 115 frost-free days, at Powder Rvr (school), WY.
What growing zone is Powder River in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −19°.
What is the best time of year to visit Powder River?
By one simple rule (highs of 62–84° and lows of 40° or more), June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Powder River getting warmer?
Yes: 1991–2020 averaged 1.6° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 66% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Powder River.
Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000; USDA/PRISM 2023 hardiness zones; FEMA National Risk Index. Today’s forecast: National Weather Service.