St. Louis weather in December: St. Louis, Missouri: normal highs, lows, rain and records for December
St. Louis in December has a normal high of 45°F and a normal low of 29°F, a daily mean of 37°F, falling from 49°F on the 1st to 41°F by the 31st. Measurable precipitation falls on 9 days in a normal December, 2.50 inches in all. (NOAA 1991-2020 normals)
In metric: a normal high of 7°C and low of −2°C, 64 mm of precipitation and 8 cm of snow in December.
- NOAA stationSt Louis Lambert International Airport
- Station IDUSW00013994
- Location38.75°N 90.37°W
- Elevation531 ft (162 m)
- From the center11 miles
- Population279,695
- Jan 40° 24°
- Feb 46° 28°
- Mar 57° 37°
- Apr 68° 47°
- May 77° 58°
- Jun 86° 67°
- Jul 90° 71°
- Aug 88° 69°
- Sep 81° 61°
- Oct 69° 49°
- Nov 56° 37°
- Dec 45° 29°
Each month: normal high (large) and low, °F. Fill: the month's normal mean, colder blue to hotter red.
How warm is St. Louis in December?
The normal high is 45°F and the normal low 29°F, for a daily mean of 36.5°F. December is 10.0°F cooler than November and 4.4°F warmer than January. December is the 11th warmest month of the year in St. Louis and the 11th wettest. Across the month the normal high falls 8°F, from 49°F on December 1 to 41°F on December 31. From one year to the next December's mean temperature typically moves about 4.3°F either way (NOAA's standard deviation), so roughly two Decembers in three average between 32°F and 41°F.
Bars above: each day's normal high to low. Columns below: the chance of 0.01 inch or more of precipitation that day, on a scale of 0 to 100% (highest 30%).
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in |
|---|---|---|---|---|
| December 1 | 49°F | 32°F | 30% | 18% |
| December 8 | 47°F | 30°F | 30% | 18% |
| December 15 | 45°F | 29°F | 30% | 17% |
| December 22 | 43°F | 27°F | 30% | 17% |
| December 31 | 41°F | 25°F | 30% | 16% |
Every day of December: normal high, low and chance of precipitation (warmest afternoon December 1, coldest night December 31)
| Day | High | Low | Chance of 0.01 in | Chance of 0.10 in | Daylight |
|---|---|---|---|---|---|
| December 1 | 49°F | 32°F | 30% | 18% | 9 h 40 min |
| December 2 | 49°F | 32°F | 30% | 18% | 9 h 40 min |
| December 3 | 48°F | 32°F | 30% | 18% | 9 h 40 min |
| December 4 | 48°F | 31°F | 30% | 18% | 9 h 40 min |
| December 5 | 48°F | 31°F | 30% | 18% | 9 h 40 min |
| December 6 | 47°F | 31°F | 30% | 18% | 9 h 40 min |
| December 7 | 47°F | 31°F | 30% | 18% | 9 h 30 min |
| December 8 | 47°F | 30°F | 30% | 18% | 9 h 30 min |
| December 9 | 46°F | 30°F | 30% | 18% | 9 h 30 min |
| December 10 | 46°F | 30°F | 30% | 18% | 9 h 30 min |
| December 11 | 46°F | 30°F | 30% | 18% | 9 h 30 min |
| December 12 | 45°F | 29°F | 30% | 18% | 9 h 30 min |
| December 13 | 45°F | 29°F | 30% | 18% | 9 h 30 min |
| December 14 | 45°F | 29°F | 30% | 18% | 9 h 30 min |
| December 15 | 45°F | 29°F | 30% | 17% | 9 h 30 min |
| December 16 | 44°F | 28°F | 30% | 17% | 9 h 30 min |
| December 17 | 44°F | 28°F | 30% | 17% | 9 h 30 min |
| December 18 | 44°F | 28°F | 30% | 17% | 9 h 30 min |
| December 19 | 44°F | 28°F | 30% | 17% | 9 h 30 min |
| December 20 | 43°F | 28°F | 30% | 17% | 9 h 30 min |
| December 21 | 43°F | 27°F | 30% | 17% | 9 h 30 min |
| December 22 | 43°F | 27°F | 30% | 17% | 9 h 30 min |
| December 23 | 43°F | 27°F | 30% | 17% | 9 h 30 min |
| December 24 | 42°F | 27°F | 30% | 17% | 9 h 30 min |
| December 25 | 42°F | 27°F | 30% | 17% | 9 h 30 min |
| December 26 | 42°F | 26°F | 30% | 17% | 9 h 30 min |
| December 27 | 42°F | 26°F | 30% | 17% | 9 h 30 min |
| December 28 | 42°F | 26°F | 30% | 17% | 9 h 30 min |
| December 29 | 41°F | 26°F | 30% | 16% | 9 h 30 min |
| December 30 | 41°F | 26°F | 30% | 16% | 9 h 30 min |
| December 31 | 41°F | 25°F | 30% | 16% | 9 h 30 min |
- Normal high
- 45°FDecember average
- Normal low
- 29°FDecember average
- Precipitation
- 2.50 inmonth total
- Days with precipitation
- 90.01 inch or more
- Snowfall
- 3.2 inmonth total
- Nights at 32°F or colder
- 20
- Daylight
- 9 h 40 min to 9 h 30 minDecember 1 to December 31
- Days at 70°F or more
- 1
- Sunshine
- 66%of clear-sky sunlight (NASA)
Source: NOAA NCEI 1991-2020 daily normals, station USW00013994; monthly normals. Daylight is computed from the place's latitude with NOAA's solar equations.
Does it rain or snow in St. Louis in December?
On a given December day the chance of 0.01 inch or more is 30% on average, highest around December 31 (30%). In all, 2.50 in falls on 9 days of a normal December.
In a normal December in St. Louis, 20 nights fall to freezing, 5 days stay below freezing all day and snowfall averages 3.2 inches.
Snow falls on 3 days in a normal December, and an inch or more covers the ground on 4 days.
Source: NOAA NCEI 1991-2020 daily and monthly normals, station USW00013994.
How humid and windy is St. Louis in December?
At 3 p.m. the normal temperature is 39°F with 58% relative humidity and a dew point of 25°F; at 6 a.m. it is 30°F with 76% humidity. The wind averages 9.4 mph, most often from the west in the afternoon. A dew point under 50°F feels dry.
| Time | Temperature | Dew point | Humidity | Wind | Clear or few clouds |
|---|---|---|---|---|---|
| 6 a.m. | 30°F | 23°F | 76% | 8.3 mph | 31% |
| 9 a.m. | 32°F | 24°F | 73% | 9.6 mph | 29% |
| noon | 37°F | 25°F | 63% | 10.8 mph | 23% |
| 3 p.m. | 39°F | 25°F | 58% | 11.1 mph | 27% |
| 6 p.m. | 36°F | 25°F | 65% | 9.4 mph | 28% |
| 9 p.m. | 34°F | 25°F | 70% | 9.4 mph | 38% |
Source: NOAA NCEI 1991-2020 hourly normals, station USW00013994. Hourly normals exist only for NOAA's first-order stations; a dash where NOAA publishes no value for that hour (the sky at some hours).
What are the records for December in St. Louis?
The warmest December temperature on St. Louis's official record (since 1874) is 78°F, on December 28, 2025; the coldest is −16°F, on December 22, 1989. The wettest December brought 11.74 in (2015); the snowiest, 26.3 inches (1973).
The December mean against the 1991-2020 normal of 36.5°F: 2021 47.0°F (+10.5), 2022 35.9°F (−0.6), 2023 45.0°F (+8.5), 2024 40.7°F (+4.2), 2025 36.1°F (−0.4). 3 of 5 ran warmer than normal.
| December | Mean | Against normal | Precip. |
|---|---|---|---|
| 2021 | 47.0°F | +10.5°F | 2.75 in |
| 2022 | 35.9°F | −0.6°F | 1.96 in |
| 2023 | 45.0°F | +8.5°F | 2.29 in |
| 2024 | 40.7°F | +4.2°F | 2.88 in |
| 2025 | 36.1°F | −0.4°F | 0.74 in |
Source: records: ACIS, NWS threaded record STLthr; recent months: ACIS, station USW00013994. Records and recent months use complete months only.
How does December in St. Louis compare across Missouri?
Across the 134 places PlainClimate covers in Missouri, December normal highs run from 37°F in Tarkio to 49°F in Neosho; St. Louis's is 45°F.
Source: NOAA NCEI 1991-2020 monthly normals for every station in the state.