Saint Charles in Winter
In winter (December, January and February), Saint Charles sees average daytime highs around 42°F and overnight lows near 27°F, with 7.6 in of precipitation over about 24 wet days across the season. It is the coldest season of the year and the driest season of the year.
Across winter, daytime highs hold fairly steady around 42°F. The sky is clear or mostly clear about 29% of the time across winter, and the air most often feels dry.
Winter is Saint Charles's weakest season of the year to visit on our travel score. For the whole year in context, see Saint Charles's year-round climate.
- Avg daytime high
- 42°F
- coldest season of the year
- Avg overnight low
- 27°F
- Precipitation
- 7.6 in
- 24 wet days
- Avg wind
- 8 mph
- Travel score
- 0.5
- weakest season of the year
- Months
- Dec · Jan · Feb
Temperature in Saint Charles in Winter
Across winter, daytime highs hold fairly steady around 42°F.
A typical winter day in Saint Charles reaches about 42°F and drops to 27°F overnight. The warmest of the three months is February, the coolest January.
How winter really feels in Saint Charles
Once humidity and wind are folded in, winter brings about 0 days that feel above 90°F and 90 that feel at or below 32°F.
The story in winter is cold — wind chill drags the overnight "feels like" below the raw low.
Saint Charles weather by month
How the three winter months (December, January and February) compare with the rest of the year — the season's months are highlighted.
| Month | High / Low (°F) | Rainfall (inches) | Wet days | Snow days | Daylight (hours) | Travel score |
|---|---|---|---|---|---|---|
| Jan | 39° / 24° | 2.6 | 8 | 3 | 9.6 | 0.0 |
| Feb | 44° / 28° | 2.4 | 7.8 | 2.8 | 10.5 | 0.8 |
| Mar | 55° / 37° | 3.7 | 10.8 | 1.4 | 11.7 | 3.5 |
| Apr | 66° / 47° | 4.5 | 11.4 | 0.2 | 13 | 5.8 |
| May | 75° / 58° | 4.9 | 13.4 | 0 | 14.1 | 6.2 |
| Jun | 84° / 67° | 4.0 | 11.2 | 0 | 14.7 | 5.4 |
| Jul | 87° / 70° | 3.3 | 9.8 | 0 | 14.4 | 4.7 |
| Aug | 86° / 68° | 2.9 | 9 | 0 | 13.5 | 5.3 |
| Sep | 79° / 60° | 3.2 | 7.6 | 0 | 12.3 | 7.1 |
| Oct | 67° / 48° | 3.4 | 8.4 | 0 | 11 | 6.6 |
| Nov | 54° / 37° | 3.6 | 8.7 | 0.8 | 9.9 | 3.5 |
| Dec | 43° / 28° | 2.5 | 8.1 | 2.2 | 9.3 | 0.6 |
Cloud cover in Winter
The sky is clear or mostly clear about 29% of the time across winter.
Chance of precipitation in Winter
Saint Charles gets around 7.6 in of rain and snow over 24 wet days across winter. The line is the day-by-day chance of measurable precipitation.
Humidity in Winter
Most of winter feels dry — the stacked bands show each day's mix of comfort levels, read off the dew point.
Wind in Winter
Winds average 8 mph across winter.
Sunrise & sunset in Winter
Daylight runs from about 9 h 30 min in early December to 11 hours by late February. The lit band spans sunrise to sunset each day.
Solar energy in Winter
Average shortwave solar energy reaching the ground each day across winter, about 2.4 kWh/m².
Hazard calendar for Saint Charles
None of Saint Charles's seasonal hazards peak in winter. The full-year calendar below shows when the rainy season, cyclone risk and dust haze do.
Saint Charles sits in the Atlantic hurricane belt; the season peaks August–October.
Is winter a good time to visit Saint Charles?
Our two travel scores rate winter for general sightseeing and for beach or pool weather — 0 (poor) to 10 (ideal), averaged across the three months.
winter is a weaker month for outdoor sightseeing in Saint Charles.
What to pack for Saint Charles in Winter
From winter's temperature range, rain chance, sun and wind — what's worth putting in the bag.
In winter, Saint Charles sees daytime highs around 42°F and nights near 27°F. Pack a warm layer and a heavy coat. Worth having: rain gear. About 24 days see rain.
UV index in Saint Charles in Winter
Clear-sky midday UV across winter averages around 2. The full-year curve, shaded by WHO exposure level, is below.
Under clear skies, the midday UV index in Saint Charles peaks around June 23 at about 9 (very high) — sunscreen, a hat and midday shade are essential. It bottoms out near January 1 at about 2 (low).
The index reaches 3 or more — the level where the WHO recommends sun protection — in 10 months of the year.
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| UV index (midday) | 2 | 3 | 5 | 7 | 8 | 9 | 9 | 8 | 7 | 4 | 3 | 2 |
| Level | Low | Moderate | Moderate | High | Very high | Very high | Very high | Very high | High | Moderate | Moderate | Low |
| UV index (midday) | Level | |
|---|---|---|
| Jan | 2 | Low |
| Feb | 3 | Moderate |
| Mar | 5 | Moderate |
| Apr | 7 | High |
| May | 8 | Very high |
| Jun | 9 | Very high |
| Jul | 9 | Very high |
| Aug | 8 | Very high |
| Sep | 7 | High |
| Oct | 4 | Moderate |
| Nov | 3 | Moderate |
| Dec | 2 | Low |
Air quality in Saint Charles in Winter
Average fine-particle pollution (PM2.5) through the year — so you can see where winter falls, not just the annual average.
Air quality in Saint Charles is worst in July — around 17 µg/m³ PM2.5 (moderate), about 2.3× the cleanest month (October, 7 µg/m³).
Modeled monthly averages (CAMS reanalysis, 2015–2024).
| Jan | Feb | Mar | Apr | May | Jun | Jul | Aug | Sep | Oct | Nov | Dec | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| PM2.5 (µg/m³) | 9 | 11 | 11 | 10 | 13 | 14 | 17 | 14 | 11 | 7 | 7 | 8 |
| Level | Good | Good | Good | Good | Moderate | Moderate | Moderate | Moderate | Good | Good | Good | Good |
| PM2.5 (µg/m³) | Level | |
|---|---|---|
| Jan | 9 | Good |
| Feb | 11 | Good |
| Mar | 11 | Good |
| Apr | 10 | Good |
| May | 13 | Moderate |
| Jun | 14 | Moderate |
| Jul | 17 | Moderate |
| Aug | 14 | Moderate |
| Sep | 11 | Good |
| Oct | 7 | Good |
| Nov | 7 | Good |
| Dec | 8 | Good |
Where is Saint Charles?
Saint Charles sits at 38.8°N, 90.5°W, 482 ft above sea level, in United States. The nearest listed city is Maryland Heights, 5.6 mi away.
Topography around Saint Charles
How much the land rises and falls, and what covers it, within 2, 10 and 50 miles of Saint Charles.
Within 2 miles, the terrain around Saint Charles has only modest variations in elevation — a maximum elevation change of 220 ft around an average of 489 ft above sea level; within 10 miles, only modest variations in elevation — a maximum elevation change of 482 ft; within 50 miles, significant variations in elevation — a maximum elevation change of 902 ft.
The land around Saint Charles is covered by artificial surfaces (43%) and trees (30%) within 2 miles, trees (34%), cropland (27%) and artificial surfaces (21%) within 10 miles, and trees (48%) and cropland (36%) within 50 miles.
United States travel facts
- Power plugs
- Type A / B
- 120 V · 60 Hz
- Prices
- ≈ 100% of US
- price level, 2025
- GDP per capita
- $90,027
- 2025
- Happiness
- 6.8 / 10
- World Happiness, 2025
- Safe drinking water
- 98%
- of population, 2024
- Homicide rate
- 5.8
- per 100k, 2023
- Road deaths
- 12.7
- per 100k/yr, 2019
- Income group
- High
- World Bank
- Religion
Sources: World Bank, US State Department, World Happiness Report, WHO/UNICEF, EF EPI, CIA World Factbook.
Data sources
Temperature, precipitation, cloud, humidity, wind and solar figures are a 1991–2020 climatology for Saint Charles (38.7839°, -90.4812°, elevation 482 ft), computed from hourly ERA5 reanalysis — contains modified Copernicus Climate Change Service information. Sun figures are astronomical calculations, not observations. City data © GeoNames, CC BY 4.0. Map outlines from Natural Earth (public domain); interactive map © Google.