What is the hottest month in St. Louis?

July is St. Louis's hottest month, with the highest average daily high of the year. The month-by-month table above shows St. Louis's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.

What is the coldest month in St. Louis?

January is St. Louis's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.

How much does it rain in St. Louis?

St. Louis's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.

What months are best to visit St. Louis?

The most comfortable months in St. Louis are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.

Has St. Louis gotten hotter?

Yes. The warming-stripes chart above plots St. Louis's annual mean temperature for every complete year of station data from 1939 to 2025, and the trend line fitted to 1939–2025 rises about 3.5°F (+0.40°F per decade) — recent decades average warmer than the start of that window.

What is the record high temperature in St. Louis?

St. Louis's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1938, so they capture the most extreme heat on record, not just a typical summer day.

What is the record low temperature in St. Louis?

St. Louis's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1938, so it reflects the coldest day on record rather than an average winter low.

St. Louis, Missouri Climate

St. Louis weather by month — average highs and lows, rainfall, all-time records, and the warming record since 1939

Hottest month: 90°FJuly average high
Coldest month: 24°FJanuary average low
Precipitation: 41.7 ina year
Snowfall: 16.6 ina year

1991–2020 NOAA climate normals

At 9:15 AM CDT on Sep 21 it was 70°F in St. Louis — 6° above the 64°F typical for that hour (estimated from the Sep 21 normal high of 79°F and low of 59°F, interpolated from the monthly normals).

St. Louis weather by month

Average high, low, and rainfall for every month, from St. Louis’s 1991–2020 climate normals, the standard 30-year reference period. Each band runs from the month’s average low to its average high: a tall band is a big day-to-night swing.

40°24°

2.6″Jan

46°28°

2.2″Feb

57°37°

3.5″Mar

68°47°

4.7″Apr

77°58°

4.8″May

86°67°

4.5″Jun

90°71°

3.9″Jul

88°69°

3.4″Aug

81°61°

3.0″Sep

69°49°

3.1″Oct

56°37°

3.4″Nov

45°29°

2.5″Dec

Average high → low (°F)Rainfall (inches)1991–2020 normals

St. Louis monthly weather averages — average high, average low, and rainfall for each month, from the 1991–2020 U.S. Climate Normals (NOAA).
Month	Avg High	Avg Low	Rainfall
January	40°F	24°F	2.6 in
February	46°F	28°F	2.2 in
March	57°F	37°F	3.5 in
April	68°F	47°F	4.7 in
May	77°F	58°F	4.8 in
June	86°F	67°F	4.5 in
July	90°F	71°F	3.9 in
August	88°F	69°F	3.4 in
September	81°F	61°F	3.0 in
October	69°F	49°F	3.1 in
November	56°F	37°F	3.4 in
December	45°F	29°F	2.5 in
Annual	67°F	48°F	41.7 in

St. Louis’s warming record since 1939

St. Louis has warmed 3.5°F since 1939 (+0.40°F per decade, 1939–2025 trend)

Not what a typical year looks like, but how the typical year has changed. Each stripe is one complete year’s average temperature at the station, 1939 to 2025, colored against the mean of those years: blue for cooler years, red for warmer ones. The figure under the stripes is the least-squares trend line fitted to 1939–2025 — St. Louis averages about 3.5°F warmer by that trend than in 1939.

Compared with the national rankingThe fastest-warming cities ranking fits every city to the same years, 1970–2025, so rates compare like for like. Over that window St. Louis warms at +0.78°F per decade, #10 of 66. The figure above uses the station’s own record, 1939–2025, so the two rates differ.

St. Louis rainfall by month

St. Louis averages 41.7 inches of precipitation a year. The wettest month is May and the driest is February.

St. Louis also averages 16.6 inches of snowfall a year.

St. Louis temperature records

All-time record high: 115°Fset July 14, 1954
All-time record low: -18°Fset January 20, 1985

Records are drawn from the nearest long-term weather station’s full daily history, so they capture the most extreme single day St. Louis has recorded — not a typical seasonal high or low.

Frequently asked

What is the hottest month in St. Louis?: July is St. Louis's hottest month, with the highest average daily high of the year. The month-by-month table above shows St. Louis's exact average high and low for each month, based on the 1991–2020 climate normals — the standard 30-year reference period meteorologists use.
What is the coldest month in St. Louis?: January is St. Louis's coldest month, with the lowest average daily low of the year. The averages-by-month chart above gives the exact average high and low for every month, so you can see how cold a typical winter day runs.
How much does it rain in St. Louis?: St. Louis's total annual precipitation and its wettest and driest months are shown in the rainfall-by-month section above. Those figures are 1991–2020 normals — the average monthly precipitation total across that 30-year window — so they reflect a typical year rather than any single wet or dry season.
What months are best to visit St. Louis?: The most comfortable months in St. Louis are usually the shoulder seasons — spring and fall — when temperatures sit between the summer peak and winter low and rainfall is moderate. Compare the average high, low, and precipitation for each month in the table above to pick the window that fits the weather you want.
Has St. Louis gotten hotter?: Yes. The warming-stripes chart above plots St. Louis's annual mean temperature for every complete year of station data from 1939 to 2025, and the trend line fitted to 1939–2025 rises about 3.5°F (+0.40°F per decade) — recent decades average warmer than the start of that window.
What is the record high temperature in St. Louis?: St. Louis's all-time record high — the hottest single day in the station record — is shown in the records section above, along with the date it occurred. Records are drawn from the nearest long-term weather station's full daily history, which begins in 1938, so they capture the most extreme heat on record, not just a typical summer day.
What is the record low temperature in St. Louis?: St. Louis's all-time record low and the date it was set appear in the records section above. Like the record high, it comes from the station's full daily history back to 1938, so it reflects the coldest day on record rather than an average winter low.