January Weather in Saint Charles, United States

Last updated: June 24, 2025

In January, the average temperature in Saint Charles, United States hovers around -8°C (18°F), but be prepared for extremes: it can plunge to a chilling -33°C (-28°F) or climb to a brisk 9°C (48°F). Expect 36 mm (1.4 in) of precipitation spread over 6 days, with the air remaining quite damp at an average humidity of 84%.

January Temperature in Saint Charles

In January in Saint Charles, the average temperature is -8°C (18°F), with maximums reaching up to 9°C (48°F) and minimums plunging as low as -33°C (-28°F). Travelers should be prepared for extreme cold and dress accordingly to enjoy their visit.

January Weather in Saint Charles: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Saint Charles, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Saint Charles, January typically has an average temperature of -8°C (18°F), with highs reaching up to 9°C (48°F) and lows dropping to around -33°C (-28°F).

Data source: Temperature data for Saint Charles generated using information from the Copernicus Climate Change Service.

January Precipitation in Saint Charles

In Saint Charles in January, the total precipitation amount is 36 mm (1.4 in), which falls over the course of 6 days.

January Precipitation Trends in Saint Charles

The chart displays monthly precipitation patterns in Saint Charles, with values for each month alongside January’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how January’s conditions compare to those of other months. In Saint Charles, January typically receives around 36 mm (1.4 inches) of precipitation spread over approximately 6 days.

Data source: Precipitation data for January generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

January Humidity in Saint Charles

In Saint Charles in January humidity is 84%. With an average temperature of -8°C (18°F), this humidity feels like a biting chill that seeps into your bones, making outdoor exploration challenging and requiring extra layers for comfort.

January Average Humidity in Saint Charles

This chart illustrates the average monthly humidity levels in Saint Charles, with January’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In January, average humidity in Saint Charles is approximately 84%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for January generated using information from the Copernicus Climate Change Service.

January UV Index in Saint Charles

In Saint Charles in January, the maximum UV index is 3, which corresponds to a moderate Exposure Category. The time to burn is approximately 30 minutes. For more details on the hourly UV index in Saint Charles, you can check the information here.

Maximum UV Index Levels in Saint Charles for January

The chart shows the monthly maximum UV Index (UVI) for Saint Charles in January, representing the highest UV radiation level. The UVI measures the intensity of ultraviolet radiation from the sun, indicating the potential risk of sunburn and UV-related health issues. In January, the maximum UV index in Saint Charles typically reaches 3, which falls under the moderate exposure category.

Data source: Saint Charles January UVI data generated using information from the Copernicus Climate Change Service.

UV Risk Categories

Extreme (11+): Avoid the sun, stay in shade.
Very High (8-10): Limit sun exposure.
High (6-7): Use SPF 30+ and protective clothing.
Moderate (3-5): Midday shade recommended.
Low (0-2): No protection needed.

How January Weather in Saint Charles Compares to Other Months

Weather in Saint Charles varies notably across the year, with each month offering distinct climate conditions. This page compares January’s weather to other months in Saint Charles, focusing on differences in temperature, rainfall, humidity, and UV levels.

This table compares monthly weather conditions in Saint Charles, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-8°C (18°F)	36 mm (1.4 inches)	84%	moderate
February Weather	-7°C (19°F)	48 mm (1.9 inches)	85%	moderate
March Weather	1°C (34°F)	57 mm (2.2 inches)	84%	moderate
April Weather	7°C (44°F)	86 mm (3.4 inches)	83%	very high
May Weather	15°C (59°F)	152 mm (6.0 inches)	75%	very high
June Weather	21°C (71°F)	151 mm (5.9 inches)	79%	very high
July Weather	23°C (74°F)	103 mm (4.1 inches)	75%	very high
August Weather	21°C (70°F)	126 mm (5.0 inches)	69%	very high
September Weather	18°C (64°F)	117 mm (4.6 inches)	74%	very high
October Weather	9°C (49°F)	118 mm (4.7 inches)	79%	moderate
November Weather	1°C (34°F)	52 mm (2.0 inches)	88%	moderate
December Weather	-4°C (26°F)	43 mm (1.7 inches)	82%	low