St Louis Weather

St Louis has a continental, temperate climate, with neither large mountains nor large bodies of water to moderate its temperature. Its location in the middle latitudes allows the area to be affected by warm, moist air that originates in the Gulf of Mexico, as well as by cold air masses that originate in Canada.

Spring and summer

Springtime, March through May, is typically the wettest season, with just under 10.5 inches of rainfall. During the summer months, air flowing in from the Gulf of Mexico tends to dominate the area, producing warm conditions. However, really hot temperatures are only expected on a few days every year. July and August are the hottest and most humid months of the year, with daily temperatures of between 14C to 32C.

Autumn and winter

Late in autumn, a period of warm weather known as Indian summer can occasionally occur, when roses are still in bloom, in November or early December some years. Winters are brisk and invigorating, and long-lasting periods of very cold weather are rare. Winter temperatures range from 0C to 12C.

Average Temperature (°C)

30 22 15 8 0

Jan -1.0

Feb 1.0

Mar 6.0

Apr 13.0

May 18.0

Jun 23.0

Jul 26.0

Aug 25.0

Sep 21.0

Oct 15.0

Nov 7.0

Dec 1.0

Rainfall (mm)

110 82 55 28 0

Jan 50.1

Feb 48.4

Mar 101.2

Apr 101.5

May 69.9

Jun 103.8

Jul 80.4

Aug 98.6

Sep 93.9

Oct 68.5

Nov 63.5

Dec 82.4