Colstrip’s winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 87°, a January night drops to 12°, and about 37 inches of snow falls in a normal winter.
A year in Colstrip at a glance
Each month’s typical high and low, and what it brings.
What stands out about Colstrip’s climate
Compared with towns across the U.S., with Colstrip’s place in Montana beside it.
What a year in Colstrip feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 138 frost-free days a year
In half of years the last 32° night comes by May 15 and the first by September 30. Frost and day counts come from NOAA’s station at Colstrip, MT, 0.2 miles from the town’s center, at about the same height.
The 2023 USDA map puts Colstrip’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 37 inches of snow a winter
Snow, measured at Colstrip, MT, is heaviest from January through February, about 7 inches a month. Precipitation (rain plus melted snow) adds up to 16 inches a year; May is the wettest month and December the driest. Rain or snow falls on about 90 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Colstrip
94% 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 Colstrip, MT.
Living with Colstrip’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
138 frost-free days in zone 5a. The last frost comes by May 15 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 30.
Months with highs of 62–84° and lows of 40° or more: May, June and September. 9.8 miles of trails are waiting.
Parks & trails →Of the yearly building losses FEMA expects in Colstrip from natural hazards, river flooding is the largest share (43%); heat waves, cold waves, winter storms and ice storms together are 43%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Colstrip and similar climates
TownRatings has no climate map of the towns around Colstrip yet.
Climates most like Colstrip’s, farther away
TownRatings’ own comparison of NOAA 1991–2020 normals, not a NOAA product: places of 5,000+ at least 150 miles away, one per state, closest on January low, July high, precipitation and snow.
| Town | Jan. low | July high | Precip. | Snow |
|---|---|---|---|---|
| Colstrip, MT | 12° | 87° | 16" | 37" |
| Glenwood Springs, CO | 14° | 87° | 15" | 39" |
| Alliance, NE | 13° | 88° | 17" | 45" |
| Rapid City, SD | 14° | 86° | 19" | 36" |
| Spring Creek, NV | 15° | 89° | 14" | 41" |
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 Colstrip averaged 1.3° warmer than the 1900s. The biggest change is in January (+4.7°).
A smaller shift than in 53% 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 Colstrip compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Colstrip’s place among Montana’s.
Colstrip weather by month
Highs, lows and precipitation from NOAA’s grid at Colstrip’s center; snow, wet days and snow on the ground from Colstrip, MT. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 35° | 12° | 0.6" | 7.4" | 7 | 18 | 13° – 35° |
| February | 37° | 14° | 0.6" | 7.3" | 6 | 14 | 6° – 36° |
| March | 48° | 22° | 0.9" | 5.5" | 8 | 9 | 22° – 44° |
| April | 57° | 31° | 1.8" | 3.3" | 9 | 3 | 38° – 48° |
| May | 66° | 40° | 3.1" | 0.5" | 12 | 0 | 48° – 58° |
| June | 77° | 49° | 2.5" | 0.0" | 11 | 0 | 57° – 67° |
| July | 87° | 56° | 1.5" | 0.0" | 7 | 0 | 62° – 77° |
| August | 86° | 53° | 1.0" | 0.0" | 6 | 0 | 64° – 75° |
| September | 75° | 43° | 1.5" | 0.2" | 6 | 0 | 54° – 66° |
| October | 59° | 32° | 1.4" | 2.3" | 7 | 2 | 37° – 52° |
| November | 45° | 22° | 0.7" | 3.9" | 6 | 6 | 22° – 43° |
| December | 35° | 14° | 0.5" | 6.2" | 6 | 13 | 13° – 33° |
| Year | 59° | 32° | 16.2" | 36.6" | 90 | 65 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 6° to 36°. May is the most reliable, staying within 10°.
Where Colstrip’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 Colstrip’s center.
- Snow: Colstrip, MT (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Colstrip, MT, 0.2 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 Colstrip’s climate
What is the weather like in Colstrip?
A typical July afternoon reaches 87°, a January night drops to 12°, and about 37 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; hotter July afternoons than 61% of U.S. towns.
How cold does it get in Colstrip in winter?
January nights average 12°. About 162 nights a year reach 32° or below and 17 reach 0° or below. In the coldest January of the last 30 years the month averaged 13°.
How much snow does Colstrip get?
About 37 inches in a normal winter at Colstrip, MT, heaviest from January through February, about 7 inches a month, with snow on the ground about 65 days a year.
How hot does it get in Colstrip?
July, with a typical high of 87° and a low of 56°. About 24 days a year reach 90° and 1 reach 100° (Colstrip, MT).
When is the first and last frost in Colstrip?
In half of years the last spring frost (32°) comes by May 15 and the first fall frost by September 30, about 138 frost-free days, at Colstrip, MT.
What growing zone is Colstrip 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 Colstrip?
By one simple rule (highs of 62–84° and lows of 40° or more), May, June and September. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Colstrip getting warmer?
Yes: 1991–2020 averaged 1.3° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 53% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Colstrip.
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.