Photo: Jon Roanhaus · CC BY-SA 4.0Big Horn gets about 81 inches of snow a winter, more than 95% of U.S. towns
Peak summer warmth arrives in July, with afternoons near 87°. Seasons differ by 76°, from the coldest nights to the warmest afternoons. Its yearly precipitation falls short of 90% of U.S. towns. Tender plants can go out after about May 17; in half of years the first frost comes by September 28.
A year in Big Horn at a glance
Each month’s typical high and low, and what it brings.
What stands out about Big Horn’s climate
Compared with towns across the U.S., with Big Horn’s place in Wyoming beside it.
What a year in Big Horn feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 132 frost-free days a year
In half of years the last 32° night comes by May 17 and the first by September 28. Frost and day counts come from NOAA’s station at Big Horn, WY, 0.6 miles from the town’s center, at about the same height.
The 2023 USDA map puts Big Horn’s center in zone 5a: the coldest night of a typical winter, averaged over 1991–2020, reaches about −18°. 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 81 inches of snow a winter
Snow, measured at Big Horn, WY, falls mostly in February. Precipitation (rain plus melted snow) adds up to 20 inches a year; May is the wettest month and January the driest. Rain or snow falls on about 106 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Big Horn
95% 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 Big Horn, WY.
Living with Big Horn’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
132 frost-free days in zone 5a. The last frost comes by May 17 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 28.
Months with highs of 62–84° and lows of 40° or more: June and September.
Parks & trails →Of the yearly building losses FEMA expects in Big Horn from natural hazards, river flooding is the largest share (53%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Big Horn and similar climates
TownRatings has no climate map of the towns around Big Horn yet.
Climates most like Big Horn’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 |
|---|---|---|---|---|
| Big Horn, WY | 12° | 87° | 20" | 81" |
| Midway, UT | 13° | 88° | 16" | 75" |
| Durango, CO | 12° | 86° | 18" | 64" |
| Spearfish, SD | 15° | 86° | 25" | 71" |
| Four Corners, MT | 14° | 84° | 15" | 91" |
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 Big Horn averaged 1.7° warmer than the 1900s. The biggest change is in January (+4.6°).
A bigger shift than in 72% 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 Big Horn compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Big Horn’s place among Wyoming’s.
Big Horn weather by month
Highs, lows and precipitation from NOAA’s grid at Big Horn’s center; snow, wet days and snow on the ground from Big Horn, WY. 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 36° | 12° | 0.8" | 11.4" | 7 | 21 | 16° – 33° |
| February | 38° | 14° | 0.9" | 16.1" | 9 | 20 | 15° – 36° |
| March | 49° | 23° | 1.6" | 13.6" | 8 | 10 | 25° – 45° |
| April | 57° | 30° | 2.6" | 10.2" | 11 | 5 | 37° – 48° |
| May | 66° | 39° | 3.6" | 2.0" | 15 | 1 | 48° – 58° |
| June | 77° | 48° | 2.3" | 0.0" | 10 | 0 | 56° – 68° |
| July | 87° | 55° | 1.3" | 0.0" | 7 | 0 | 62° – 76° |
| August | 86° | 52° | 0.8" | 0.0" | 7 | 0 | 63° – 73° |
| September | 75° | 43° | 1.7" | 1.0" | 7 | 0 | 54° – 64° |
| October | 60° | 31° | 2.3" | 6.2" | 10 | 2 | 37° – 52° |
| November | 46° | 21° | 1.1" | 9.2" | 7 | 8 | 24° – 43° |
| December | 36° | 12° | 0.9" | 11.7" | 6 | 20 | 16° – 31° |
| Year | 59° | 32° | 19.7" | 81.4" | 106 | 88 |
How much a month can swing
A normal is an average. February swings the most: from 1991 to 2020 its average ranged from 15° to 36°. May is the most reliable, staying within 10°.
Where Big Horn’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 Big Horn’s center.
- Snow: Big Horn, WY (NOAA station in town).
- Frost, freezing nights, 90° and 100° days, heating and cooling: Big Horn, WY, 0.6 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 Big Horn’s climate
What is the weather like in Big Horn?
A typical July afternoon reaches 87°, a January night drops to 12°, and about 81 inches of snow falls in a normal winter. Colder January nights than 92% of U.S. towns; hotter July afternoons than 63% of U.S. towns.
How cold does it get in Big Horn in winter?
January nights average 12°. About 177 nights a year reach 32° or below and 18 reach 0° or below. In the coldest January of the last 30 years the month averaged 16°.
How much snow does Big Horn get?
About 81 inches in a normal winter at Big Horn, WY, most of it in February, with snow on the ground about 88 days a year.
How hot does it get in Big Horn?
July, with a typical high of 87° and a low of 55°. About 23 days a year reach 90° (Big Horn, WY).
When is the first and last frost in Big Horn?
In half of years the last spring frost (32°) comes by May 17 and the first fall frost by September 28, about 132 frost-free days, at Big Horn, WY.
What growing zone is Big Horn in?
Zone 5a on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about −18°.
What is the best time of year to visit Big Horn?
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 Big Horn getting warmer?
Yes: 1991–2020 averaged 1.7° warmer than 1901–2000 on NOAA’s grid. A bigger shift than 72% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Big Horn.
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.