Gillette, WY climate
Gillette has cold, snowy winters and warm summers, with very little rain. A typical July afternoon reaches 86°, a January night drops to 13°, and about 56 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Gillette feels like
Winter
Spring
Summer
Fall
Gillette weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | Snow | Wet days | Snow on ground | 30-yr range |
|---|---|---|---|---|---|---|---|
| January | 35° | 13° | 0.5" | 8.2" | 8 | 16 | 15° – 35° |
| February | 36° | 14° | 0.6" | 9.0" | 8 | 14 | 11° – 35° |
| March | 47° | 23° | 1.0" | 8.6" | 8 | 8 | 23° – 45° |
| April | 55° | 29° | 1.9" | 9.4" | 11 | 4 | 35° – 47° |
| May | 65° | 39° | 3.0" | 1.3" | 13 | 0 | 46° – 58° |
| June | 76° | 48° | 2.3" | 0.1" | 10 | 0 | 55° – 69° |
| July | 86° | 55° | 1.6" | 0 | 8 | 0 | 61° – 76° |
| August | 85° | 53° | 1.2" | 0 | 6 | 0 | 64° – 74° |
| September | 74° | 44° | 1.1" | 0.5" | 6 | 0 | 52° – 64° |
| October | 59° | 32° | 1.5" | 4.4" | 8 | 2 | 36° – 51° |
| November | 45° | 21° | 0.6" | 5.8" | 6 | 7 | 21° – 44° |
| December | 35° | 14° | 0.5" | 8.4" | 7 | 14 | 14° – 30° |
| Year | 58° | 32° | 15.7" | 55.7" | 100 | 66 |
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain and snow in Gillette
Gillette gets 16 inches of rain and melted snow a year. May is the wettest month and January the driest. Rain or snow falls on about 100 days a year. Snow covers the ground about 66 days of the year.
About 136 frost-free days a year
In half of years the last 32° night comes by May 15 and the first one by October 1. That leaves about 136 frost-free days for gardens, shorter than 92% of U.S. towns.
Heating and cooling a home in Gillette
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Gillette, 93% of that work is heating and 7% is cooling, so the furnace matters far more than the air conditioner.
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
How Gillette compares
Compared with every U.S. town and city on TownTapestry, each counted once.
Warmer than it used to be
The last 30 years in Gillette averaged 1.8° warmer than the 1900s. The biggest change is in January (+4.5°). The shift is larger than in 87% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Gillette’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. February swings the most: between 1991 and 2020 its average temperature ranged from 11° to 35°. August is the most reliable, staying within 10°.
Common questions about Gillette’s climate
What is the coldest month in Gillette?
January, with a typical high of 35° and a low of 13°.
What is the hottest month in Gillette?
July, with a typical high of 86° and a low of 55°. About 28 days a year reach 90°.
How much snow does Gillette get?
About 56 inches in a normal winter, most of it in April.
When is the first frost in Gillette?
In half of years the first 32° night comes by October 1, and the last spring frost by May 15.
What is the rainiest month in Gillette?
May, with 3.0 inches of rain and melted snow. The year totals 16 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Gillette itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Gillette 4se, WY (2 mi) away. Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.