Glen Allen, MO climate
Glen Allen has chilly winters and warm summers, with plenty of rain. A typical July afternoon reaches 89°, a January night drops to 24°, and about 8 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Glen Allen feels like
Winter
Spring
Summer
Fall
Glen Allen 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 | 30-yr range |
|---|---|---|---|---|---|---|
| January | 43° | 24° | 3.3" | 2.2" | 10 | 27° – 42° |
| February | 48° | 28° | 3.2" | 1.2" | 8 | 27° – 46° |
| March | 58° | 36° | 4.4" | 1.5" | 11 | 40° – 58° |
| April | 69° | 45° | 5.5" | 0 | 11 | 50° – 63° |
| May | 78° | 55° | 5.5" | 0 | 12 | 62° – 73° |
| June | 86° | 64° | 3.9" | 0 | 9 | 69° – 80° |
| July | 89° | 67° | 4.3" | 0 | 9 | 73° – 84° |
| August | 88° | 65° | 3.5" | 0 | 8 | 72° – 83° |
| September | 81° | 57° | 3.4" | 0 | 7 | 65° – 76° |
| October | 70° | 45° | 3.8" | 0.1" | 8 | 53° – 63° |
| November | 57° | 35° | 4.5" | 0.1" | 9 | 39° – 51° |
| December | 46° | 28° | 3.8" | 2.4" | 9 | 24° – 46° |
| Year | 68° | 46° | 49.1" | 7.5" | 111 |
“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 Glen Allen
Glen Allen gets 49 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 111 days a year.
About 193 frost-free days a year
In half of years the last 32° night comes by April 12 and the first one by October 23. That leaves about 193 frost-free days for gardens, longer than 67% of U.S. towns.
Heating and cooling a home in Glen Allen
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Glen Allen, 72% of that work is heating and 28% is cooling.
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 Glen Allen 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 Glen Allen averaged 0.5° warmer than the 1900s. The biggest change is in February (+1.4°). The shift is smaller than in 97% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Glen Allen’s spot on NOAA’s grid
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 24° to 46°. October is the most reliable, staying within 10°.
Common questions about Glen Allen’s climate
What is the coldest month in Glen Allen?
January, with a typical high of 43° and a low of 24°.
What is the hottest month in Glen Allen?
July, with a typical high of 89° and a low of 67°. About 38 days a year reach 90°.
How much snow does Glen Allen get?
About 8 inches in a normal winter, most of it in December.
When is the first frost in Glen Allen?
In half of years the first 32° night comes by October 23, and the last spring frost by April 12.
What is the rainiest month in Glen Allen?
May, with 5.5 inches of rain and melted snow. The year totals 49 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Glen Allen itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Jackson, MO (20 mi, snow) and Marble Hill, MO (4 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.