January Weather in Alton, United States

Last updated: June 24, 2025

In January, the average temperature in Alton, United States hovers around -5°C (24°F), with minimums plunging to -25°C (-13°F) and maximums reaching 15°C (59°F). Expect about 75 mm (2.9 in) of precipitation spread over 8 days, paired with an average humidity of 86%.

January Temperature in Alton

In January in Alton, the average temperature is -5°C (24°F). Maximums can reach 15°C (59°F), and minimums can be as low as -25°C (-13°F). Travelers should be prepared for a wide range of temperatures while visiting this destination.

January Weather in Alton: Daily Temperature Highs, Lows, and Averages

The chart illustrates January temperature patterns in Alton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Alton, January typically has an average temperature of -5°C (24°F), with highs reaching up to 15°C (59°F) and lows dropping to around -25°C (-13°F).

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

January Precipitation in Alton

In Alton in January, the precipitation amount is 75 mm (2.9 in) over a span of 8 days.

January Precipitation Trends in Alton

The chart displays monthly precipitation patterns in Alton, 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 Alton, January typically receives around 75 mm (2.9 inches) of precipitation spread over approximately 8 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 Alton

In Alton in January, humidity is 86%. With an average temperature of -5°C (24°F), this humidity feels like a damp chill that seeps into your bones, making traveling uncomfortable as even the slightest breeze becomes biting, and your clothing clings uncomfortably to your skin.

January Average Humidity in Alton

This chart illustrates the average monthly humidity levels in Alton, 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 Alton is approximately 86%, 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 Alton

In Alton 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 Alton, you can check the information here.

Maximum UV Index Levels in Alton for January

The chart shows the monthly maximum UV Index (UVI) for Alton 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 Alton typically reaches 3, which falls under the moderate exposure category.

Data source: Alton 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 Alton Compares to Other Months

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

This table compares monthly weather conditions in Alton, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-5°C (24°F)	75 mm (2.9 inches)	86%	moderate
February Weather	-3°C (27°F)	84 mm (3.3 inches)	84%	moderate
March Weather	0°C (33°F)	77 mm (3.0 inches)	82%	moderate
April Weather	7°C (44°F)	128 mm (5.0 inches)	80%	very high
May Weather	13°C (56°F)	74 mm (2.9 inches)	72%	very high
June Weather	19°C (66°F)	87 mm (3.4 inches)	72%	very high
July Weather	22°C (72°F)	134 mm (5.3 inches)	67%	very high
August Weather	21°C (71°F)	74 mm (2.9 inches)	66%	very high
September Weather	18°C (64°F)	66 mm (2.6 inches)	71%	high
October Weather	11°C (52°F)	119 mm (4.7 inches)	78%	moderate
November Weather	3°C (39°F)	110 mm (4.3 inches)	84%	moderate
December Weather	-2°C (29°F)	119 mm (4.7 inches)	81%	low