January Weather in Alton, United States

Last updated: June 24, 2025

In Alton, United States, the average temperature in January hovers around 16°C (62°F), offering a comfortably mild experience. However, be prepared for temperature fluctuations, as it can dip to a brisk -1°C (31°F) or soar to a warm 34°C (94°F). Rainfall is moderate, with 20 mm (0.8 in) of precipitation expected over about 4 days. Visitors can anticipate a high average humidity of 83%, adding a touch of tropical warmth to the atmosphere.

January Temperature in Alton

In January in Alton, the average temperature is 16°C (62°F). Maximum temperatures can reach up to 34°C (94°F), while minimums can drop as low as -1°C (31°F). This variability in weather conditions makes Alton an ideal destination for travelers seeking a diverse climate experience.

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 16°C (62°F), with highs reaching up to 34°C (94°F) and lows dropping to around -1°C (31°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 total precipitation amount is 20 mm (0.8 in) spread over a period of 4 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 20 mm (0.8 inches) of precipitation spread over approximately 4 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 83%. With an average temperature of 16°C (62°F), this humidity feels like a warm, sticky embrace that can make traveling feel a bit heavy, leaving you longing for refreshing breezes and shaded spots to relax in.

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 83%, 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 6, which corresponds to a high Exposure Category. The time to burn is approximately 25 minutes. To find the hourly UV index in Alton, you can refer to this Hourly UV Index in Alton.

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 6, which falls under the high 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	16°C (62°F)	20 mm (0.8 inches)	83%	high
February Weather	18°C (65°F)	21 mm (0.8 inches)	79%	very high
March Weather	22°C (72°F)	31 mm (1.2 inches)	76%	very high
April Weather	25°C (78°F)	31 mm (1.2 inches)	77%	extreme
May Weather	28°C (83°F)	87 mm (3.4 inches)	80%	extreme
June Weather	30°C (86°F)	81 mm (3.2 inches)	73%	extreme
July Weather	30°C (87°F)	100 mm (3.9 inches)	66%	extreme
August Weather	31°C (88°F)	22 mm (0.9 inches)	65%	extreme
September Weather	29°C (84°F)	96 mm (3.8 inches)	73%	extreme
October Weather	25°C (77°F)	51 mm (2.0 inches)	76%	very high
November Weather	20°C (69°F)	30 mm (1.2 inches)	80%	high
December Weather	18°C (64°F)	21 mm (0.8 inches)	86%	high