January Weather in Alton, United States

Last updated: June 24, 2025

In January, the average temperature in Alton, United States hovers around 0°C (32°F). Expect a chill in the air, with minimum temperatures dipping as low as -22°C (-8°F), while the daytime can reach a pleasant 19°C (66°F). During this month, precipitation averages at 73 mm (2.9 in) over 8 days, contributing to an overall average humidity of 82%. Be prepared for a mix of crisp air and occasional wet weather!

January Temperature in Alton

In January in Alton, the average temperature is 0°C (32°F). Maximum can reach 19°C (66°F) and minimum can be as low as -22°C (-8°F). It's advisable to pack both warm and light clothing if you're planning to travel during this time.

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 0°C (32°F), with highs reaching up to 19°C (66°F) and lows dropping to around -22°C (-8°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 73 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 73 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.

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

January Humidity in Alton

In Alton in January, humidity is 82%. With an average temperature of 0°C (32°F), this humidity feels like an icy breath enveloping you, making each step outdoors a challenge as the cold dampness seeps into your clothes, chilling you to the bone and sapping your energy while traveling.

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 82%, 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	0°C (32°F)	73 mm (2.9 inches)	82%	moderate
February Weather	1°C (35°F)	78 mm (3.1 inches)	80%	moderate
March Weather	8°C (46°F)	132 mm (5.2 inches)	80%	high
April Weather	12°C (55°F)	123 mm (4.9 inches)	80%	very high
May Weather	19°C (67°F)	150 mm (5.9 inches)	82%	very high
June Weather	25°C (77°F)	101 mm (4.0 inches)	83%	extreme
July Weather	26°C (79°F)	96 mm (3.8 inches)	81%	extreme
August Weather	24°C (76°F)	119 mm (4.7 inches)	80%	very high
September Weather	22°C (72°F)	67 mm (2.6 inches)	76%	very high
October Weather	15°C (59°F)	100 mm (3.9 inches)	76%	high
November Weather	6°C (44°F)	70 mm (2.8 inches)	85%	moderate
December Weather	3°C (38°F)	54 mm (2.1 inches)	86%	moderate