🎶 St. Louis Weather

Where the Midwest meets the muggy South

St. Louis sits near the confluence of the Mississippi and Missouri rivers, at the transition between the humid continental Midwest and the humid subtropical South. The result is a climate of extremes packed into one city — some of the hottest, stickiest summers in the Midwest, genuinely cold winters, and a full menu of severe weather in between.

Sweltering summers

Summers are hot and oppressively humid, with July highs in the upper 80s to low 90s°F (around 31–33°C) and a heat index that frequently soars past 100°F (38°C). The dense urban core amplifies the heat, and the 1980 and 1995 heat waves rank among the deadliest weather events in the city's history.

Cold winters and ice

Winters are cold and changeable, with January highs around 40°F (4°C). The city sits right on the rain–snow line, so winter storms can bring anything from heavy snow to a destructive glaze of ice. Spring brings the severe-weather season, with thunderstorms, hail, and tornadoes possible across the region.

St. Louis averages about 41 inches (1,040 mm) of precipitation a year, peaking in spring. The wide rivers also make the metro vulnerable to major flooding, as the historic Great Flood of 1993 made unforgettable.

Continental extremes at the confluence

Where the Missouri joins the Mississippi, St. Louis sits at a climatic crossroads that gives it some of the widest temperature swings of any big US city — brutally hot, humid summers and genuinely cold winters, sometimes just days apart.

Summer heat indices routinely top 105°F (41°C), and the city's brick-and-concrete core intensifies the mugginess after dark. It sits on the edge of Tornado Alley, so spring brings a real severe-storm threat, while winter delivers a volatile mix of snow, ice, and freezing rain depending on which air mass wins out.