More precipitation falls on Glen Allen than on 81% of U.S. towns: 49 inches a year
Peak summer warmth arrives in July, with afternoons near 89°. May is the wettest month, February the driest. Summer afternoons here are warmer than in 72% of U.S. towns. The outdoor season, with highs of 69–81°, runs through April, May, September and October.
A year in Glen Allen at a glance
Each month’s typical high and low, and what it brings.
What stands out about Glen Allen’s climate
Compared with towns across the U.S., with Glen Allen’s place in Missouri beside it.
What a year in Glen Allen feels like
Typical highs and lows by season and by month, from NOAA’s 30-year normals.
About 193 frost-free days a year
In half of years the last 32° night comes by April 12 and the first by October 23. Frost and day counts come from NOAA’s station at Marble Hill, MO, 4 miles from the town’s center, at about the same height.
The 2023 USDA map puts Glen Allen’s center in zone 6b: the coldest night of a typical winter, averaged over 1991–2020, reaches about 0°. 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 8 inches of snow a winter
Snow, measured at Jackson, MO, falls mostly in January and December. Precipitation (rain plus melted snow) adds up to 49 inches a year; May is the wettest month and February the driest. Rain or snow falls on about 111 days a year.
Rain + melted snow by month
Inches of water
Snowfall by month
Inches of snow
Heating and cooling a home in Glen Allen
72% of the work is heating. Months averaging under 55° run from November through March.
Degree days add up how far each day’s average falls below (heating) or rises above (cooling) 65° over a year. NOAA normals at Marble Hill, MO.
Living with Glen Allen’s climate
What the numbers mean for a garden, a free afternoon and a bad-weather day.
193 frost-free days in zone 6b. The last frost comes by Apr 12 in half of years, so many gardeners wait a week or two past that to set out tomatoes. The first fall frost comes by Oct 23.
Months with highs of 62–84° and lows of 40° or more: April, May, September and October.
Parks & trails →Of the yearly building losses FEMA expects in Glen Allen from natural hazards, river flooding is the largest share (46%); heat waves, cold waves, winter storms and ice storms together are 12%. Normals are averages; the hazards page covers the extremes.
Natural hazards →Glen Allen and similar climates
TownRatings has no climate map of the towns around Glen Allen yet.
Climates most like Glen Allen’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 |
|---|---|---|---|---|
| Glen Allen, MO | 24° | 89° | 49" | 7.5" |
| Owensboro, KY | 25° | 88° | 48" | 5.7" |
| Pea Ridge, AR | 26° | 89° | 47" | 9.5" |
| Boonville, IN | 24° | 88° | 49" | 11" |
| Norristown, PA | 23° | 88° | 48" | 7.6" |
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 Glen Allen averaged 0.5° warmer than the 1900s. The biggest change is in February (+1.4°).
A smaller shift than in 98% 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 Glen Allen compares
Against 12,954 U.S. towns of 2,500 or more (one per 5 km climate cell), with Glen Allen’s place among Missouri’s.
Glen Allen weather by month
Highs, lows and precipitation from NOAA’s grid at Glen Allen’s center; snow, wet days and snow on the ground from Jackson, MO. 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" | 0.0" | 11 | 50° – 63° |
| May | 78° | 55° | 5.5" | 0.0" | 12 | 62° – 73° |
| June | 86° | 64° | 3.9" | 0.0" | 9 | 69° – 80° |
| July | 89° | 67° | 4.3" | 0.0" | 9 | 73° – 84° |
| August | 88° | 65° | 3.5" | 0.0" | 8 | 72° – 83° |
| September | 81° | 57° | 3.4" | 0.0" | 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 |
How much a month can swing
A normal is an average. December swings the most: from 1991 to 2020 its average ranged from 24° to 46°. October is the most reliable, staying within 10°.
Where Glen Allen’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 Glen Allen’s center.
- Snow: Jackson, MO.
- Frost, freezing nights, 90° and 100° days, heating and cooling: Marble Hill, MO, 4 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 Glen Allen’s climate
What is the weather like in Glen Allen?
A typical July afternoon reaches 89°, a January night drops to 24°, and about 8 inches of snow falls in a normal winter. Milder January nights than 60% of U.S. towns; hotter July afternoons than 72% of U.S. towns.
How cold does it get in Glen Allen in winter?
January nights average 24°. About 95 nights a year reach 32° or below and 2 reach 0° or below. In the coldest January of the last 30 years the month averaged 27°.
How much snow does Glen Allen get?
About 7.5 inches in a normal winter at Jackson, MO, most of it in January and December.
How hot does it get in Glen Allen?
July, with a typical high of 89° and a low of 67°. About 38 days a year reach 90° and 1 reach 100° (Marble Hill, MO).
When is the first and last frost in Glen Allen?
In half of years the last spring frost (32°) comes by April 12 and the first fall frost by October 23, about 193 frost-free days, at Marble Hill, MO.
What growing zone is Glen Allen in?
Zone 6b on the 2023 USDA Plant Hardiness Zone Map: the coldest night of a typical winter reaches about 0°.
What is the best time of year to visit Glen Allen?
By one simple rule (highs of 62–84° and lows of 40° or more), April, May, September and October. The rule is ours, not NOAA’s; the month table has the numbers to judge by.
Is Glen Allen getting warmer?
Yes: 1991–2020 averaged 0.5° warmer than 1901–2000 on NOAA’s grid. A smaller shift than 98% of U.S. towns.
Neighbors talk weather
Gardens, snow, and the best days of the year in Glen Allen.
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.