St. Louis has chilly winters and warm summers. A typical July afternoon reaches 88°, a January night drops to 24°, and about 14 inches of snow falls in a normal winter.
NOAA 1991-2020 climate normalsUpdated once a decade
☀️
July high
88°
527th hottest of 1,353 Missouri towns
❄️
January low
24°
289th mildest of 1,353 Missouri towns
💧
Rain + melted snow
42 in
568th driest of 1,353 Missouri towns
🌨️
Snow a winter
14 in
523rd snowiest of 1,335 Missouri towns
A normal year
What a year in St. Louis feels like
❄️
Winter
43° / 26°
Typical high / low · 5 days with an inch or more of snow
🌷
Spring
67° / 46°
Typical high / low · Last frost around Apr 1
☀️
Summer
87° / 67°
Typical high / low · 47 days reach 90° in a normal year
🍂
Fall
68° / 48°
Typical high / low · First frost around Nov 4
10°
20°
40°
50°
60°
70°
80°
90°
100°
32°
40°
24°
45°
27°
56°
36°
68°
45°
77°
56°
85°
66°
88°
69°
87°
67°
80°
59°
69°
47°
55°
37°
44°
28°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
32°, freezingBar runs from the typical overnight low up to the afternoon high
Best months to be outsideAprMaySepOctHighs of 62–84° and lows of 40° or more
Month by month
St. Louis weather by month
Average highs, lows, rain and snow for every month, from NOAA’s 1991–2020 normals.
Month
High
Low
Rain + melt
Snow
Wet days
Snow on ground
30-yr range
January
40°
24°
2.5"
4.9"
9
7
26° – 42°
February
45°
27°
2.1"
3.7"
8
4
27° – 46°
March
56°
36°
3.4"
1.2"
10
1
39° – 59°
April
68°
45°
4.6"
0.3"
12
0
49° – 63°
May
77°
56°
4.9"
0
12
0
61° – 74°
June
85°
66°
4.4"
0
10
0
70° – 80°
July
88°
69°
3.9"
0
8
0
74° – 86°
August
87°
67°
3.4"
0
8
0
72° – 83°
September
80°
59°
3.4"
0
7
0
65° – 76°
October
69°
47°
3.1"
0
8
0
53° – 64°
November
55°
37°
3.4"
0.8"
8
1
38° – 53°
December
44°
28°
2.7"
2.9"
10
4
22° – 44°
Year
66°
47°
41.7"
13.8"
111
15
“Wet days” have at least 0.01" of rain or melted snow. “Snow on ground” counts days with 1" or more. The 30-year range is the coldest and warmest that month’s average temperature got between 1991 and 2020.
Rain & snow
Rain and snow in St. Louis
St. Louis gets 42 inches of rain and melted snow a year. May is the wettest month and February the driest. Rain or snow falls on about 111 days a year. Snow covers the ground about 15 days of the year.
💧
42 in
Rain + melted snow a year
More rain than 57% of U.S. towns
❄️
14 in
Snow in a normal winter
Less snow than 67% of U.S. towns
⛄
15 days
With 1"+ of snow on the ground
Fewer than 63% of U.S. towns
Rain + melted snow by month
Inches of water
4.9"
JFMAMJJASOND
Snowfall by month
Inches of snow
4.9"
JFMAMJJASOND
Frost & the growing season
About 218 frost-free days a year
In half of years the last 32° night comes by April 1 and the first one by November 4. That leaves about 218 frost-free days for gardens, longer than 81% of U.S. towns.
🌱 Apr 1
🍂 Nov 4
218 frost-free days
JFMAMJJASOND
🥶
79
nights at or below 32° in a normal year
🧊
<1
nights below 0° in a normal year
🔥
47
days that reach 90° in a normal year
Freezing nights by month
Average nights at or below 32°
JFMAMJJASOND
90° days by month
Average days at 90° or more
JFMAMJJASOND
Heating & cooling
Heating and cooling a home in St. Louis
Engineers use “degree days” to estimate how hard a furnace or air conditioner works. In St. Louis, 71% of that work is heating and 29% is cooling.
🔥
4,292 heating degree daysLess heating than 76% of U.S. towns
❄️
1,769 cooling degree daysMore cooling than 85% of U.S. towns
Degree days measure how far each day’s average temperature falls below or rises above 65°, added up over a year. Source: NOAA station normals.
Around St. Louis
St. Louis and its neighbors
St. Louis borders 12 towns with climate data. January nights across them vary by 0.3°. Venice has the coldest January nights (23°) and Lemay the hottest July afternoons (89°). St. Louis’s January low is 24° and its July high 88°.
Compared with every U.S. town and city on TownTapestry, each counted once.
Then and now
Warmer than it used to be
+1.0°1991–2020 average vs. the 20th century (1901–2000)
The last 30 years in St. Louis averaged 1.0° warmer than the 1900s. The biggest change is in December (+2.1°). The shift is smaller than in 69% of U.S. towns.
❄️ Winter+1.8°now 35°, was 33°
🌷 Spring+1.3°now 56°, was 55°
☀️ Summer+0.4°now 77°, was 77°
🍂 Fall+0.5°now 58°, was 57°
Change by month1991–2020 average minus 1901–2000 average, at St. Louis’s spot on NOAA’s grid
−0.1°
+2.1°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Year to year
How much a month can swing
A normal is an average, and real years wander around it. December swings the most: between 1991 and 2020 its average temperature ranged from 22° to 44°. June is the most reliable, staying within 9°.
10°
20°
30°
40°
50°
60°
70°
80°
90°
100°
JanJFebFMarMAprAMayMJunJJulJAugASepSOctONovNDecD
Coldest to warmest month in 30 yearsNormal
Questions
Common questions about St. Louis’s climate
What is the coldest month in St. Louis?
January, with a typical high of 40° and a low of 24°.
What is the hottest month in St. Louis?
July, with a typical high of 88° and a low of 69°. About 47 days a year reach 90°.
How much snow does St. Louis get?
About 14 inches in a normal winter, most of it in January.
When is the first frost in St. Louis?
In half of years the first 32° night comes by November 4, and the last spring frost by April 1.
What is the rainiest month in St. Louis?
May, with 4.9 inches of rain and melted snow. The year totals 42 inches.
📍Temperatures and rainfall come from NOAA’s gridded climate normals for St. Louis itself (about a 3-mile square). Snow, frost dates and day counts come from NOAA’s weather station at Cahokia, IL (5 mi, snow) and St Louis Sci Ctr, MO (1 mi, frost, heat and degree days). Normals are 30-year averages, not a forecast. Source: NOAA NCEI U.S. Climate Normals, 1991–2020 and 1901–2000.