Clarkson Valley, MO climate
Clarkson Valley has chilly winters and warm summers. A typical July afternoon reaches 89°, a January night drops to 23°, and about 8 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normals Updated once a decadeWhat a year in Clarkson Valley feels like
Winter
Spring
Summer
Fall
Clarkson Valley 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 | 40° | 23° | 2.5" | 4.2" | 7 | 25° – 42° |
| February | 46° | 26° | 2.2" | 1.1" | 8 | 26° – 46° |
| March | 56° | 35° | 3.5" | 0.3" | 10 | 38° – 59° |
| April | 68° | 45° | 4.7" | 0 | 10 | 49° – 62° |
| May | 76° | 55° | 4.9" | 0 | 12 | 61° – 73° |
| June | 85° | 64° | 4.5" | 0 | 9 | 70° – 79° |
| July | 89° | 68° | 3.8" | 0 | 8 | 73° – 85° |
| August | 87° | 66° | 3.7" | 0 | 7 | 71° – 83° |
| September | 80° | 58° | 3.3" | 0 | 6 | 64° – 76° |
| October | 69° | 46° | 3.1" | 0 | 8 | 52° – 63° |
| November | 55° | 36° | 3.4" | 0.4" | 8 | 38° – 52° |
| December | 44° | 27° | 2.6" | 2.1" | 8 | 22° – 44° |
| Year | 66° | 46° | 42.2" | 8.1" | 101 |
“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 Clarkson Valley
Clarkson Valley gets 42 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 101 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 Clarkson Valley
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In Clarkson Valley, 76% of that work is heating and 24% 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.
Clarkson Valley and its neighbors
Clarkson Valley borders 4 towns with climate data. January nights across them vary by 0.4°. Wildwood has the coldest January nights (22°) and Ballwin the hottest July afternoons (88°). Clarkson Valley’s January low is 23° and its July high 89°.
Temperatures and rain come from NOAA’s 5 km grid, so each town gets its own value.
How Clarkson Valley 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 Clarkson Valley averaged 1.0° warmer than the 1900s. The biggest change is in February (+2.0°). The shift is smaller than in 73% of U.S. towns.
Change by month1991–2020 average minus 1901–2000 average, at Clarkson Valley’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 22° to 44°. June is the most reliable, staying within 9°.
Common questions about Clarkson Valley’s climate
What is the coldest month in Clarkson Valley?
January, with a typical high of 40° and a low of 23°.
What is the hottest month in Clarkson Valley?
July, with a typical high of 89° and a low of 68°. About 44 days a year reach 90°.
How much snow does Clarkson Valley get?
About 8 inches in a normal winter, most of it in January.
When is the first frost in Clarkson Valley?
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 Clarkson Valley?
May, with 4.9 inches of rain and melted snow. The year totals 42 inches.
Temperatures and rainfall come from NOAA’s gridded climate normals for Clarkson Valley itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at St Charles 7 Ssw, MO (6 mi, snow) and St Louis Sprt Of S L Airport, 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.