St. Charles, MO

Climate overview — based on NOAA 1991-2020 normals from ST CHARLES ELM PT, MO US.

Dfa Hot-summer humid continental climate 7b USDA hardiness Zone 7b

Year-round temperatures (°F)

20° 40° 60° 80° J F M A M J J A S O N D
Avg high Avg low

Climate summary

St. Charles has an annual average temperature of 55.5°F with about 45.7 inches of precipitation per year and 9 inches of snow. The warmest month is July (average high 88.0°F), and the coldest is January (average low 21.9°F). May is typically the wettest month (5.45 in) and January the driest (2.74 in). Snow typically falls from December through March.

Pleasant months
1 / 12
avg high 65–80°F, low ≥ 50°F
Annual swing
47.5°F
warmest to coldest month
Heating need
4,551
Cooling need
1,140

Best time to visit St. Charles

Full guide →

Climate change signal

All-time records →

24 of 366 (6.6%) of St. Charles's all-time daily heat records have been set since 2015. If records were spread evenly across the station's history, only about 5% would fall in any given decade.

1890s
10
1900s
22
1910s
33
1920s
27
1930s
102
1940s
32
1950s
50
1960s
11
1970s
16
1980s
15
1990s
7
2000s
14
2010s
12
2020s
15

Bars: number of all-time daily heat records still standing that were set in each decade.

Monthly averages

Month Avg High Avg Low Avg Temp Precipitation Snow Rainy days
January 39.5°F 21.9°F 30.7°F 2.74 in 4.3 in 8
February 44.7°F 25.2°F 35.0°F 2.86 in 2.6 in 7
March 55.2°F 33.7°F 44.4°F 3.63 in 0.5 in 10
April 66.8°F 44.0°F 55.4°F 5.11 in 10
May 76.0°F 55.1°F 65.5°F 5.45 in 11
June 84.1°F 64.3°F 74.2°F 4.35 in 9
July 88.0°F 68.3°F 78.2°F 4.20 in 8
August 86.8°F 65.8°F 76.3°F 4.07 in 7
September 80.4°F 57.2°F 68.8°F 3.08 in 7
October 68.8°F 45.7°F 57.3°F 3.50 in 8
November 55.3°F 35.3°F 45.3°F 3.73 in 0.1 in 8
December 44.1°F 26.4°F 35.2°F 2.99 in 1.5 in 7

Climate twins of St. Charles

Why these? →

The most climatically similar US cities at least 140 miles away (by monthly temperature + precipitation pattern).

Frost dates
Last spring / first fall frost
All-time records
Hottest, coldest, wettest
Planting calendar
What to plant, and when

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