Weather in St. Louis

Weather — St. Louis, United States

St. Louis weather brings four distinct seasons: cold, occasionally snowy winters; a wet, changeable spring; hot, humid summers ideal for outdoor festivals and swimming; and a pleasant, colorful autumn. This page gives a month-by-month look at what to expect so you can pick the best time to visit, pack smart, and find the right flights to St. Louis.

Weather — St. Louis — January

January is the coldest month in St. Louis with average highs near 5°C and nighttime lows dipping below freezing. Expect several frosty days, occasional light snow, and limited sunshine — dress in layers and a warm coat if you plan urban sightseeing around the Gateway Arch.

Weather — St. Louis — February

February remains brisk but starts to hint at spring: daytime temperatures typically reach about 8°C while nights can still freeze. Precipitation is moderate and sunny breaks are limited, so bring a waterproof jacket and warm layers for walking tours and indoor attractions.

Weather — St. Louis — March

March is a transitional month — milder afternoons around 14°C make outdoor exploration more appealing, but showers and occasional late frosts are common. It’s a good time to catch early spring events, though keep an umbrella handy for sudden rain.

Weather — St. Louis — April

April brings reliably warmer weather with average highs near 20°C, yet it’s one of the wetter months. Expect frequent rain showers mixed with sunny spells — perfect weather for city parks coming alive, but plan flexible outdoor activities.

Weather — St. Louis — May

May typically feels like late spring turning into summer: pleasant daytime temperatures around 25°C, warm nights, and a fair share of rain. It’s an excellent month for riverfront strolls and early outdoor festivals, though humidity and periodic thunderstorms begin to increase.

Weather — St. Louis — June

June is the start of summer warmth with average highs near 30°C and many sunny days — ideal for swimming, outdoor concerts, and exploring nearby parks. Expect occasional heavy showers or thunderstorms, so plan water-friendly activities but check forecasts for storm windows.

Weather — St. Louis — July

July is the hottest month in St. Louis, often topping 30°C with a number of very hot days. High humidity can make it feel even warmer; this is prime season for pool time, riverfront events, and air-conditioned indoor sightseeing. Stay hydrated and seek shade during midday.

Weather — St. Louis — August

August remains hot and humid with average highs around 30°C and plenty of sun. Rainfall generally decreases compared with late spring, but summer storms still occur. It’s a great month for late-night festivals and enjoying St. Louis’s outdoor dining — just expect summer heat.

Weather — St. Louis — September

September cools down to comfortable highs near 27°C with more sunny days and lower humidity, making it one of the nicest months to visit. Ideal for walking the city, riverfront parks, and fall events — evenings turn crisper, so pack a light layer.

Weather — St. Louis — October

October delivers classic autumn weather: mild days around 20°C, clear skies, and colorful foliage. It’s a top month for sightseeing, brewery tours, and outdoor dining — comfortable daytime temperatures and pleasant evenings.

Weather — St. Louis — November

November brings a steady cool-down with daytime highs near 13°C and an increasing chance of frosty nights. Expect more overcast and rainy days; it’s a quieter travel period good for museums and indoor attractions if you prefer fewer crowds.

Weather — St. Louis — December

December ushers in winter conditions with daytime temperatures around 7°C and nighttime lows below freezing at times. Light snow is possible but heavy accumulation is uncommon; festive holiday events and indoor comforts make it a cozy month to visit.

Temperature table for the year