St Louis, MO Climate: Temperature & Rain by Month
Pulled from NOAA NCEI 1991–2020 normals →: climate measurements used in PlainClimate's documented score
30-year climate normals (1991-2020) from St Louis's primary NOAA station, ST LOUIS LAMBERT INTL AP.
The climate verdict for St Louis
St Louis, Missouri has a mixed annual climate rather than one dominant extreme. Its NOAA normal shows an annual average of 57°F. It scores 78/100 for climate comfort (good), putting it in the top third of station-mapped location scores and exceeding 72% of them.
- 57°F
- annual average temperature (NOAA normal)
- 78/100
- comfort score, above 72% of station-mapped location scores
- 41.7"
- annual precipitation · 17" snow
- 216 days
- growing season, frost-free days
St Louis: NOAA 1991-2020 normals describe a typical year, not a forecast. Method: /methodology.
Normals record plate
Sheet USW00013994 · St Louis, MO 57°F mean · 41.7" precip
TEMP-MILD · RANK-UPPER · PHOTO-FINISH · PRCP-MID · SWING-WIDE · COMF-TOP · LOAD-HEAT · STN-1 · BOOK-FULL
- TEMP-MILD 57°F
- RANK-UPPER #4,665
- PHOTO-FINISH ≈ Freedom
- PRCP-MID 41.7"
- SWING-WIDE 48°F
- COMF-TOP 78/100
- LOAD-HEAT 4,433 HDD
- STN-1 USW00013994
- BOOK-FULL 6/6 fields
Nearest mean-temperature peer: Freedom, OK (+ 0 °F mean)
Instrument codes from this station's NOAA 1991–2020 normals, mean temperature, corpus warmth rank, photo-finish peer station, precipitation band, seasonal swing, comfort composite, degree-day load, and field book, not a livability rating.
Mean-temperature neighbourhood
Nationwide NOAA normal poles and nearest peers, not a reprint of every MO station list.
- Hot Gate, OK 58°F
- Near Jefferson, OK 58°F
- Near Moab, UT 58°F
- St Louis (this station) 57°F
- Near Freedom, OK 57°F
Climate Living Index · St Louis
St Louis: 66/100 · grade C
St Louis publishes all six Living Index dimensions from NOAA annual/seasonal normals · NOAA daily multivariate normals · NOAA hourly normals.
PlainClimate-derived for St Louis, not an official NOAA rating. Rankings still use Comfort Score 78/100 (separate formula). Breakpoints and limits.
| Dimension | Station value | Score |
|---|---|---|
| Normal heat + freeze calendar | 91 calendar days | 79/100 · B |
| Precipitation balance | 41.7 in · 6.7 from 35 in | 76/100 · B |
| Frost-free season | 216 days/year | 75/100 · B |
| Annual temperature balance | 57.4°F · 10.1° from 67.5°F | 68/100 · C |
| Snowfall burden | 16.6 inches/year | 53/100 · D |
| Summer moisture balance | 65.3°F mean dew point | 34/100 · F |
St Louis · 2026-08-04 · NOAA NCEI Climate Normals · method · Comfort Score method.
St Louis is a temperate Köppen climate: Cfa
Coldest-month mean 32.1°F and warmest-month mean 80.4°F place this station in temperate, no dry season, hot summer climates (Cfa). Class Cfa is the Peel et al. (2007) label for this station's monthly mean temperature and precipitation normals: temperate, specifically temperate, no dry season, hot summer.
- Köppen code
- Cfa
- Group
- Temperate
- Warmest month
- 80.4°F
- Coldest month
- 32.1°F
Source: official public datasets monthly normals (1991–2020) at the city’s primary station. This is a station classification, not a mapped regional consensus.
National standing · heating-led station
Where St Louis sits across the climate record
Three NOAA fields for St Louis's primary station, temperature, precipitation, and seasonal swing, are ranked against every station-mapped normal that carries the same field.
- Annual temperature
- 68th percentile warmth
- Mid-pack annual mean versus 6,861 station normals.
- Annual precipitation
- 62nd percentile wetness
- Neither arid nor torrential versus 6,352 station totals.
- Seasonal temperature swing
- Wider than 75%
- Warmest-to-coldest month gap for St Louis is large versus 6,861 complete station-years.
How St Louis compares across U.S. station-mapped locations
St Louis's comfort score vs. all station-mapped locations
PlainClimate composite comfort index (1–100), NOAA 1991–2020 normals
78 Top 28% score exceeds 72% of 6,189 station-mapped location scores
- 0–10: 0 station-mapped locations (0%). Below this entry.
- 10–20: 0 station-mapped locations (0%). Below this entry.
- 20–30: 96 station-mapped locations (2%). Below this entry.
- 30–40: 280 station-mapped locations (5%). Below this entry.
- 40–50: 1,113 station-mapped locations (18%). Below this entry.
- 50–60: 1,329 station-mapped locations (21%). Below this entry.
- 60–70: 1,236 station-mapped locations (20%). Below this entry.
- 70–80: 650 station-mapped locations (11%). This entry sits in this band.
- 80–90: 921 station-mapped locations (15%). Above this entry.
- 90–100: 564 station-mapped locations (9%). Above this entry.
Source NOAA U.S. Climate Normals, PlainClimate comfort index · 1991–2020
St Louis's measured station temperature trend
MethodologyAcross 83 complete annual observations from 1939 to 2025, ST LOUIS LAMBERT INTL AP warmed at a fitted rate of 0.13°C per decade. The line shows the fitted change relative to its first year, not raw year-to-year temperatures or a forecast.
- St Louis primary station fitted change +0.13 °C/decade
Monthly Temperatures
Average daily high and low temperatures by month
| Month | Avg High | Avg Low | Mean | Precip | Snow | Freeze Days | 90°F+ Days |
|---|---|---|---|---|---|---|---|
| January | 40°F (5°C) | 24°F (-5°C) | 32°F (0°C) | 2.6" | 5.7" | 24.1 | 0.0 |
| February | 46°F (8°C) | 28°F (-2°C) | 37°F (3°C) | 2.2" | 4.3" | 18.9 | 0.0 |
| March | 57°F (14°C) | 37°F (3°C) | 47°F (8°C) | 3.5" | 2.3" | 10.3 | 0.0 |
| April | 68°F (20°C) | 47°F (8°C) | 58°F (14°C) | 4.7" | 0.2" | 1.4 | 0.3 |
| May | 77°F (25°C) | 58°F (14°C) | 68°F (20°C) | 4.8" | 0.0" | 0.0 | 1.9 |
| June | 86°F (30°C) | 67°F (20°C) | 77°F (25°C) | 4.5" | 0.0" | 0.0 | 10.6 |
| July | 90°F (32°C) | 71°F (22°C) | 80°F (27°C) | 3.9" | 0.0" | 0.0 | 15.9 |
| August | 88°F (31°C) | 69°F (21°C) | 79°F (26°C) | 3.4" | 0.0" | 0.0 | 13.0 |
| September | 81°F (27°C) | 61°F (16°C) | 71°F (22°C) | 3.0" | 0.0" | 0.0 | 5.0 |
| October | 69°F (21°C) | 49°F (10°C) | 59°F (15°C) | 3.1" | 0.0" | 0.6 | 0.4 |
| November | 56°F (13°C) | 37°F (3°C) | 47°F (8°C) | 3.4" | 0.9" | 9.1 | 0.0 |
| December | 45°F (7°C) | 29°F (-2°C) | 37°F (3°C) | 2.5" | 3.2" | 20.4 | 0.0 |
The year, day by day
Summer here tops out rather than builds: the warmest normal high is 90°F around July 15, short of 90°F on every date, while 91 dates carry a normal low at or below freezing, the coldest 23°F near January 16.
The freezing stretch
The normal low stays at or below 32°F into March 1, then returns to freezing around December 2, covering 91 dates in all.
Derived from the normal daily minimum. This is a different measure from the 50%-probability frost dates shown elsewhere on this page, which come from NOAA’s frost product.
Where the wet dates fall
The likeliest wet date is May 2, when 42% of years recorded at least a hundredth of an inch. The driest is September 13 at 25%. Summed across the calendar, that is about 114 wet dates a year.
The widest day
April 7 carries the biggest normal gap between afternoon and dawn, 21°F between the normal high and the normal low.
Look up any date
Any date's 1991–2020 normal for St Louis.
Where St Louis Stands Nationally
Among the steadiest day-night climates ranked: even the widest normal daily swing holds to roughly 21°F.
St Louis earns one nationally notable standing (outer quintile) against 6,860 NOAA 1991–2020 normals stations, middle-of-the-pack metrics stay silent here.
Monthly Precipitation
Average monthly rainfall and snowfall
Snow: 5.7"
9.3 days with precipitation
Snow: 4.3"
8.7 days with precipitation
Snow: 2.3"
10.8 days with precipitation
Snow: 0.2"
11.5 days with precipitation
12.6 days with precipitation
9.8 days with precipitation
8.9 days with precipitation
8.4 days with precipitation
7.3 days with precipitation
8.5 days with precipitation
Snow: 0.9"
9.0 days with precipitation
Snow: 3.2"
9.0 days with precipitation
St Louis spreads its precipitation across the year
Neither half of the year dominates here: June through August take 28% of the annual total and December through February 18%, with neither reaching the 35% that would mark a distinct wet season. St Louis has no dry season to plan around, though it does carry a wide 48.3°F gap between its warmest and coldest month.
The gap between the wettest and driest month still matters: May averages 4.8" and February 2.2". The three wettest months together take 34% of the year, against the 25% a perfectly flat distribution would give them.
Shares are computed from this station's own 1991-2020 monthly precipitation normals. "Spread across the year" means neither the June-August nor the December-February share reaches 35%; it describes an average year, not the variability of any single one.
When it rains in St Louis, it arrives in quantity
41.7" of precipitation falls across only about 114 wet days here, averaging 0.37 inches each. Fewer days carry more water: the year's total is delivered in comparatively heavy events rather than persistent damp.
- Days with measurable precipitation
- about 114 a year, 31% of all days
- Average depth per wet day
- 0.37 inches
- Most wet days
- May, about 13
- Fewest wet days
- September, about 7
A wet day is one recording at least 0.01 inches. These are 1991-2020 normals: they describe an average year, and a per-day average is not a forecast of any individual storm.
Winter brings real snow to St Louis
St Louis averages 16.6 inches of snowfall a year, with January the snowiest month on the normals, spread across roughly 15 days that record measurable snow. That is depth accumulating on the ground, which is why it can exceed the annual precipitation figure: precipitation counts the liquid the snow melts down to, and fresh snow is mostly air.
- Annual snowfall: 16.6 inches of depth.
- Days recording measurable snow: about 15 a year.
- At a rough ten-to-one melt ratio, snow accounts for on the order of 4% of the year's precipitation.
NOAA 1991-2020 normals. The ten-to-one ratio is a convention, not a measurement: real ratios vary with temperature, so treat the share as an order of magnitude rather than an exact split.
Frost Dates & Growing Season
First Fall Freeze
November 4
50% probability date
Last Spring Freeze
April 2
50% probability date
Growing Season
216 days
Heating & Cooling Degree Days
Annual totals indicate energy demand for heating and cooling
Heating Degree Days
4,433
Higher = more heating needed
Cooling Degree Days
1,713
Higher = more cooling needed
Warmest Month
July
Coldest Month
January
Humidity & Wind
Monthly averages from hourly observations
| Month | Humidity | Wind (mph) | Clear Sky % | Overcast % |
|---|---|---|---|---|
| January | 65% | 9.5 | 17% | 42% |
| February | 62% | 10.4 | 18% | 42% |
| March | 59% | 10.3 | 17% | 36% |
| April | 62% | 9.6 | 14% | 38% |
| May | 64% | 8.4 | 11% | 30% |
| June | 64% | 7.8 | 21% | 19% |
| July | 65% | 7.1 | 17% | 18% |
| August | 66% | 7.0 | 22% | 17% |
| September | 63% | 7.8 | 33% | 18% |
| October | 64% | 8.9 | 23% | 33% |
| November | 66% | 9.6 | 18% | 40% |
| December | 69% | 9.4 | 19% | 45% |
Nationwide similar cities
Other rankable U.S. places outside MO closest to St Louis on two NOAA annual-normal axes (mean temperature and annual precipitation). Chip rows use distinct link sets.
Closest by average temperature
Nearest out-of-state peers by annual mean temperature (57°F here).
- Anthony, KS 57°F · 0.0°F off
- Cookeville, TN 57°F · 0.0°F off
- Elkton, KY 57°F · 0.0°F off
- Freedom, OK 57°F · 0.0°F off
Closest by annual precipitation
Nearest out-of-state peers by annual precipitation (41.7" here), excluding temperature-peer places.
- Bangor, ME 41.7" · 0.0" off
- Madison, ME 41.7" · 0.0" off
- Mccoll, SC 41.7" · 0.0" off
- Meyersdale, PA 41.7" · 0.0" off
Snow and freeze rhythm
When cold and snow define St Louis
heating led · moderate · mid swing
St Louis's energy balance leans toward cold weather: 4,433 annual heating degree days against 1,713 for cooling. Its 48.3°F seasonal range still makes the monthly rows more useful than the annual average alone.
St Louis's frost-free season lasts about 216 days, a middle-length window whose endpoints matter more than the annual average. It describes freeze probability, not year-specific planting conditions.
-
1. St Louis coldest normal
January
The monthly mean of 32°F (0°C) sits near freezing, so cold nights and above-freezing afternoons share the same month.
-
2. St Louis typical freeze period
January through December
The station reports average freezing days from January through December.
-
3. St Louis snow peak
January
St Louis averages 16.6 inches of snow a year, with January the snowiest month on the normals.
Questions about St Louis's climate
How much snow does St Louis get? ▼
How many days above 90°F does St Louis get? ▼
How much energy does heating and cooling require in St Louis? ▼
Data Sources
Data source: NOAA U.S. Climate Normals v1.0.1 (1991-2020). All figures on this page are from St Louis's primary station: ST LOUIS LAMBERT INTL AP (USW00013994). For informational purposes only.
Place identity: U.S. Census Bureau 2024 Gazetteer places. The 2024 Census Gazetteer identifies the exact name-and-state match as an incorporated place (GEOID 2965000). Match rule for St Louis: exact normalized name + state only, no fuzzy expansion, so nearby differently spelled facilities stay unmatched.
On this page every temperature, precipitation, and derived score for St Louis comes from its primary NOAA station record. No figure on this page is typed in by an editor - each value is rendered from NOAA 1991-2020 U.S. Climate Normals. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error. Data current as of 1991–2020 normals.