St. Louis averages 44.8 days a year above 90°F, with May the wettest month at 4.84 in of normal rain. The hottest day on record was 107°F on Jun 28, 2012; the coldest, −14°F on Jan 7, 2014. The single biggest 24-hour rain event recorded was 7.23 in on Jul 26, 2022.
Climate and Average Weather Year Round in St. Louis
Year-round temperature
In St. Louis, the warmest months are June through September, with average daily highs between 81°F and 89°F. The coldest stretch runs December through February, with highs between 40°F and 46°F and overnight lows reaching 24°F.
Rainfall through the year
Rainfall in St. Louis averages 3.4 in per month over the long run. May is the wettest at 4.8 in, while February is the driest at 2.0 in.
Days at 90 °F or hotter
St. Louis averages 44.8 days per year at 90 °F or hotter. The hottest year on record saw 75 such days (2012); the coolest just 3 (2026).
Precipitation this year
As of May 28, St. Louis has received 11.4 in of precipitation this year — 31% below the long-term normal for this point in the year (16.5 in).