The climate of St. Louis
Belonging to the humid subtropical climate zone,
St. Louis,
Missouri, encounters a variety of weather conditions over the course of the year. This milieu is primarily characterized by its lack of a dry season, with sufficient moisture persisting year-round. This city's geographic position, nestled along the Mississippi River in the central United States, adds another layer of environmental complexity, strongly influencing its observed weather patterns.
Examining the weather patterns, it becomes clear that St. Louis experiences a pronounced shift in various climatic parameters throughout the year. During
January, the coldest month, temperatures often plummet to 23.7°F (-4.6°C), while during
July, they can rocket up to a sweltering 89.1°F (31.7°C). Humidity levels remain relatively stable, albeit with minor fluctuations between 63.5% in
April and 75.8% in
December. Rainfall varies from 2.2" (56mm) in
February to 4.7" (119mm) in
May, accompanied by a shift in rainy days from 8 in February to 11.9 in May. Particularly interesting is the significant absence of snow from May to
November, with January and December recording the highest snowfall of 5.6 and 4.4" (112mm), respectively.
The city's weather also showcases some unique patterns. Even though July and
August are the warmest months, these months do not record the highest rainfall. Instead, May records the highest rainfall. On the other hand, St. Louis experiences no snowfall from May to November, a characteristic weather pattern for a subtropical climate.
The best time to visit St. Louis
A visit to
St. Louis is most enjoyable during spring and fall due to mild temperatures and lower humidity levels. Particularly, the months of
April and
May offer comfortable conditions with temperatures ranging from 47.2°F (8.4°C) to 67.4°F (19.7°C) and humidity around 63.5%. In the fall,
September and
October are perfect months to experience the city as temperatures rest from 49°F (9.4°C) to 68.5°F (20.3°C) with a balanced humidity around 68.7%.
The worst time to visit St. Louis
St. Louis can exhibit extreme weather conditions during the summer and winter. The summer months from
June to
August, with temperatures varying from 76.3°F (24.6°C) to 89.1°F (31.7°C) and high humidity levels, could make outdoor activities a challenge. In the winter,
December to
February, temperatures often plummet to below freezing and St Louis experiences significant snowfall, making it a difficult period for travel and outdoor adventures.
Spring weather in St. Louis
Spring in
St. Louis is a time of gradual warming, with temperatures routinely ranging from 36.6°F (2.6°C) to 67.4°F (19.7°C). Rainfall rates rise during this season, peaking at 4.7" (119mm) in
May. Spring is also unique in that it tends to be relatively sunny with daylight hours increasing from 12 hours in
March to 14.3 hours in May, and sunshine hours rising to 8.6 hours per day by May.
Summer weather in St. Louis
Summer brings persistent heat to
St. Louis. Throughout this season, temperatures consistently hover between a comfortable 57.2°F (14°C) and a searing 89.1°F (31.7°C). Humidity levels elevate during the summer months as well, peaking at 68% in
July. Despite these conditions, St. Louis experiences a dip in rainfall in summer, a stark contrast to spring’s considerable precipitation.
Autumn weather in St. Louis
Autumn is a pleasant season in
St. Louis as temperatures cool from the intense summer heat. Throughout the fall, daily highs slide from 80.2°F (26.8°C) in
September to 42.5°F (5.8°C) by
December, creating a refreshing transition into winter. The autumn months bring a relatively fair share of rainfall to the city, in amounts ranging from 3" (76mm) in September to 2.8" (71mm) in December.
Winter weather in St. Louis
Winter in
St. Louis is characterized by cold temperatures and significant snowfall. With lows of 23.7°F (-4.6°C) in
January and highs only reaching 42.5°F (5.8°C) in
December, the city definitely experiences a cold season. Alongside, there is distinguished snowfall, particularly in January, which receives an average of 5.6" (142mm) of snow over 4.7 days during the month.
Weather in January
January in
St. Louis begins the year firmly within the grips of the winter season. Freezing conditions are predominant, with the lowest mean temperature of 23.7°F (-4.6°C). Winterscape often includes snowfall totaling 5.6" (142mm) across the city.
Weather in January » Weather in February
February sees a slight easing of
January’s harsh winter conditions; days start to lengthen and temperatures, albeit marginally, show an upward trend appreciably. The average temperature rises from January but the conditions remain chilly at 27.6°F (-2.4°C).
Weather in February » Weather in March
March is characteristic of transitional weather in
St. Louis,
Missouri. The mercury level steadily rises, hinting at the forthcoming arrival of spring. This month sees a significant jump in average temperatures to 36.6°F (2.6°C). The snowfall finally dwindles, signaling the end of the winter season.
Weather in March »
Weather in April
April in
St. Louis signifies the full-fledged arrival of spring. A significant improvement in weather conditions becomes evident with the mean temperature increasing substantially. The temperature ranges from 47.2°F (8.4°C), warming the day considerably.
Weather in April » Weather in May
May dawns with improved weather conditions and temperatures, making it ideal for outdoor activities and explorations. The high temperatures rise further, granting the city a pleasant, slightly warm ambiance. The city basks in the highest average temperatures of 57.2°F (14°C) experienced this year.
Weather in May » Weather in June
St. Louis experiences the official advent of summer in
June. Temperatures continue their upward incline, creating warm, typically summery conditions. Average daytime temperatures climb to a pleasant 66.8°F (19.3°C), perfect for enjoying an outdoor picnic or a leisurely day boating on the Mississippi.
Weather in June »
Weather in July
July is the warmest month of the year in
St. Louis. High temperatures reach their zenith in this month, registering an all-year high of 71°F (21.7°C). Residents and tourists alike eagerly anticipate the quintessential southern summer, filled with sunny days and warm nights.
Weather in July » Weather in August
The weather in
August carries forward the warmth and high humidity of
July. Despite a slight dip in temperatures, the average remains notably high at 69.4°F (20.8°C).
St. Louis continues to bask in long daylight hours, frequently punctuated by sudden bursts of summer rainstorms.
Weather in August »Weather in September
September is a transitional month, marking the beginning of fall in
St. Louis,
Missouri. As the month progresses, daily temperatures gradually drop, providing relief from the summer heat. The average temperature lowers to a comfortable 60.6°F (15.9°C).
Weather in September »
Weather in October
October brings the full splendor of autumn to
St. Louis with its vibrant foliage and crisp air. Temperatures maintain a steady drop, bestowing upon the city a temperate and clear climate throughout October. The temperature averages about 49°F (9.4°C), ideal for exploring the city's stunning autumn-accented landscapes.
Weather in October » Weather in November
November in
St. Louis represents late fall, with residents preparing for the upcoming winter season. Average temperatures decline appreciably, providing a noticeable chill indicative of the approaching winter. Around this time, the city experiences a low temperature of 38.1°F (3.4°C).
Weather in November » Weather in December
December in
St. Louis is firmly within the winter season. Bitter cold conditions greet residents, often accompanied by snow. Temperatures plummet to their second-lowest of the year, averaging at 26.9°F (-2.8°C). As a result, the city experiences winter's first significant snowfall since the onset of the year-end season.
Weather in December »