Carbella Bridge · Photo: Robstutz · CC BY-SA 3.0Corwin Springs’ winters are colder and snowier than most of the U.S.
A typical July afternoon reaches 83°, a January night drops to 12°, and about 72 inches of snow falls in a normal winter.
A year in Corwin Springs at a glance
Each month’s typical high and low, and what it brings.
What stands out about Corwin Springs’ climate
Compared with towns across the U.S., with Corwin Springs’ place in Montana beside it.
What a year in Corwin Springs feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 102 frost-free days a year
In half of years the last 32° night comes by June 3 and the first by September 14. Day counts come from NOAA’s station at Gardiner, MT, 8 miles from the town’s center, at about the same height; frost dates and degree days from Yellowstone Park Mammoth, WY, 12 miles away.
The 2023 USDA map puts Corwin Springs’ center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −17°. 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 72 inches of snow a winter
Snow, measured at Yellowstone Park Mammoth, WY, falls mostly in January, February and December. Precipitation (rain plus melted snow) adds up to 15 inches a year; June is the wettest month and February the driest. Rain or snow falls on about 127 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Corwin Springs
99% of the work is heating, so the furnace matters far more than the air conditioner. Months averaging under 55° run from September 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 Yellowstone Park Mammoth, WY.
Living with Corwin Springs’ climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
102 frost-free days in zone 5a. The last frost comes by Jun 3 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 14.
Months with highs of 62–84° and lows of 40° or more: June, July and August.
Parks & trails →Of the yearly building losses FEMA expects in Corwin Springs from natural hazards, avalanches are the largest share (82%); heat waves, cold waves, winter storms and ice storms together are 1%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Corwin Springs and similar climates
TownRatings has no climate map of the towns around Corwin Springs yet.
Climates most like Corwin Springs’, 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 |
|---|---|---|---|---|
| Corwin Springs, MT | 12° | 83° | 15" | 72" |
| Ranchettes, WY | 16° | 85° | 16" | 65" |
| Durango, CO | 12° | 86° | 18" | 64" |
| Flagstaff, AZ | 16° | 84° | 18" | 90" |
| Hailey, ID | 10° | 84° | 14" | 102" |
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 Corwin Springs averaged 1.2° warmer than the 1900s. The biggest change is in March (+3.2°).
A smaller shift than in 62% 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 Corwin Springs compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Corwin Springs’ place among Montana’s.
Corwin Springs weather by month
Highs, lows and precipitation from NOAA’s grid at Corwin Springs’ center; snow, wet days and snow on the ground from Yellowstone Park Mammoth, WY. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 32° | 12° | 0.8" | 11.5" | 11 | 31 | 15° – 28° |
| February | 36° | 13° | 0.7" | 11.5" | 11 | 27 | 15° – 32° |
| March | 45° | 21° | 1.1" | 10.9" | 11 | 19 | 24° – 39° |
| April | 53° | 27° | 1.7" | 7.8" | 11 | 6 | 35° – 45° |
| May | 63° | 35° | 2.0" | 1.7" | 13 | 1 | 43° – 53° |
| June | 73° | 42° | 2.3" | 0.3" | 13 | 0 | 51° – 63° |
| July | 83° | 47° | 1.2" | 0.0" | 9 | 0 | 55° – 71° |
| August | 82° | 45° | 1.1" | 0.0" | 9 | 0 | 58° – 68° |
| September | 72° | 38° | 1.2" | 0.6" | 9 | 0 | 51° – 59° |
| October | 56° | 29° | 1.4" | 4.7" | 10 | 3 | 33° – 50° |
| November | 41° | 20° | 1.0" | 9.9" | 10 | 16 | 22° – 40° |
| December | 31° | 12° | 0.9" | 12.6" | 12 | 28 | 15° – 26° |
| Year | 56° | 28° | 15.4" | 71.5" | 127 | 131 |
How much a month can swing
A normal is an average. November swings the most: from 1991 to 2020 its average ranged from 22° to 40°. September is the most reliable, staying within 8°.
Where Corwin Springs’ 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 Corwin Springs’ center.
- Snow: Yellowstone Park Mammoth, WY.
- Frost dates, heating and cooling: Yellowstone Park Mammoth, WY, 12 miles away.
- Freezing nights, 90° and 100° days: Gardiner, MT, 8 miles from the town’s center, at about the same height; no station nearby passes every check; this is the nearest one in the same valley, flagged above.
- 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 Corwin Springs’ climate
What is the weather like in Corwin Springs?
A typical July afternoon reaches 83°, a January night drops to 12°, and about 72 inches of snow falls in a normal winter. Colder January nights than 91% of U.S. towns; cooler July afternoons than 70% of U.S. towns.
How cold does it get in Corwin Springs in winter?
December nights average 12°. About 167 nights a year reach 32° or below and 10 reach 0° or below. In the coldest December of the last 30 years the month averaged 15°.
How much snow does Corwin Springs get?
About 72 inches in a normal winter at Yellowstone Park Mammoth, WY, most of it in January, February and December, with snow on the ground about 131 days a year.
How hot does it get in Corwin Springs?
July, with a typical high of 83° and a low of 47°. About 26 days a year reach 90° (Yellowstone Park Mammoth, WY).
When is the first and last frost in Corwin Springs?
In half of years the last spring frost (32°) comes by June 3 and the first fall frost by September 14, about 102 frost-free days, at Yellowstone Park Mammoth, WY.
What growing zone is Corwin Springs in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −17°.
What is the best time of year to visit Corwin Springs?
By one simple rule (highs of 62–84° and lows of 40° or more), June, July and August. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Corwin Springs getting warmer?
Yes: 1991–2020 averaged 1.2° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 62% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Corwin Springs.
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.