Climate & Weather in O'Fallon
O'Fallon has a real, genuine four-season St. Louis-metro climate, with warm, humid summers and cold winters, plus a real, elevated spring severe-weather season.
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Learn moreWarm, humid summers; cold winters
O'Fallon's climate follows the St. Louis metro's real humid-continental/subtropical-transition pattern, with warm, humid summers and genuinely cold winters.
A real, elevated spring severe-weather season
O'Fallon shares the St. Louis metro's real, statistically elevated spring tornado and severe-thunderstorm season, part of the broader Missouri pattern documented in missouri.js.
Four real, distinct seasons
O'Fallon experiences four genuinely distinct seasons, consistent with the broader St. Louis metro climate pattern.
Key takeaways
- O'Fallon's climate follows the St. Louis metro's humid four-season pattern.
- O'Fallon shares the St. Louis metro's real, elevated spring severe-thunderstorm and tornado season.
- O'Fallon experiences cold winters and warm, humid summers typical of the St. Louis metro.
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