Glenrock, WY climate
Glenrock has cold winters and warm summers, with very little rain. A typical July afternoon reaches 88°, a January night drops to 14°.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Glenrock feels like
Winter
Spring
Summer
Fall
Glenrock weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
| Month | High | Low | Rain + melt | 30-yr range |
|---|---|---|---|---|
| January | 38° | 14° | 0.4" | 20° – 32° |
| February | 39° | 15° | 0.5" | 20° – 35° |
| March | 50° | 23° | 0.8" | 28° – 43° |
| April | 57° | 29° | 1.6" | 37° – 49° |
| May | 67° | 39° | 2.4" | 47° – 59° |
| June | 79° | 47° | 1.4" | 56° – 69° |
| July | 88° | 54° | 1.0" | 64° – 75° |
| August | 86° | 52° | 0.8" | 64° – 72° |
| September | 76° | 42° | 1.0" | 54° – 65° |
| October | 61° | 31° | 1.1" | 37° – 52° |
| November | 47° | 22° | 0.5" | 22° – 43° |
| December | 37° | 14° | 0.5" | 18° – 30° |
| Year | 60° | 32° | 11.8" |
“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 Glenrock
Glenrock gets 12 inches of rain and melted snow a year. May is the wettest month and January the driest.
About 143 frost-free days a year
In half of years the last 32° night comes by May 12 and the first one by October 1. That leaves about 143 frost-free days for gardens, shorter than 87% of U.S. towns.
Heating and cooling a home in Glenrock
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Glenrock, 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 Glenrock 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 Glenrock averaged 1.4° warmer than the 1900s. The biggest change is in January (+3.7°). The shift is larger than in 67% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Glenrock’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. November swings the most: between 1991 and 2020 its average temperature ranged from 22° to 43°. August is the most reliable, staying within 8°.
Common questions about Glenrock’s climate
What is the coldest month in Glenrock?
December, with a typical high of 37° and a low of 14°.
What is the hottest month in Glenrock?
July, with a typical high of 88° and a low of 54°. About 29 days a year reach 90°.
When is the first frost in Glenrock?
In half of years the first 32° night comes by October 1, and the last spring frost by May 12.
What is the rainiest month in Glenrock?
May, with 2.4 inches of rain and melted snow. The year totals 12 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Glenrock itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Casper 1sw, WY (22 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.