January Weather in Thornton, United States

Last updated: June 24, 2025

In January, the average temperature in Thornton, United States hovers around -8°C (18°F), with extremes ranging from a chilling -29°C (-20°F) to a milder 12°C (54°F). Expect about 85 mm (3.4 in) of precipitation over 11 days, while the air remains notably humid with an average humidity level of 86%. Prepare accordingly for the brisk weather!

January Temperature in Thornton

In January in Thornton, the average temperature is -8°C (18°F). Maximum temperatures can reach 12°C (54°F) and minimums can drop as low as -29°C (-20°F). Be prepared for a wide temperature range and dress accordingly for your travels!

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

The chart illustrates January temperature patterns in Thornton, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Thornton, January typically has an average temperature of -8°C (18°F), with highs reaching up to 12°C (54°F) and lows dropping to around -29°C (-20°F).

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

January Precipitation in Thornton

In Thornton in January, the precipitation amount is 85 mm (3.4 in) over the course of 11 days.

January Precipitation Trends in Thornton

The chart displays monthly precipitation patterns in Thornton, 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 Thornton, January typically receives around 85 mm (3.4 inches) of precipitation spread over approximately 11 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 Thornton

In Thornton in January, humidity is 86%. With an average temperature of -8°C (18°F), this humidity feels like a biting chill that seeps into your bones, making travel uncomfortable and frigid, as the damp air accentuates the cold, creating a sharp contrast that can be quite challenging for outdoor activities.

January Average Humidity in Thornton

This chart illustrates the average monthly humidity levels in Thornton, 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 Thornton 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 Thornton

In Thornton 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 Thornton, you can check the information here.

Maximum UV Index Levels in Thornton for January

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

Data source: Thornton 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 Thornton Compares to Other Months

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

This table compares monthly weather conditions in Thornton, 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)	85 mm (3.4 inches)	86%	moderate
February Weather	-6°C (21°F)	86 mm (3.4 inches)	84%	moderate
March Weather	-2°C (28°F)	75 mm (2.9 inches)	82%	high
April Weather	5°C (41°F)	129 mm (5.1 inches)	80%	very high
May Weather	12°C (53°F)	98 mm (3.9 inches)	72%	very high
June Weather	17°C (63°F)	105 mm (4.1 inches)	72%	very high
July Weather	20°C (68°F)	135 mm (5.3 inches)	67%	very high
August Weather	19°C (66°F)	99 mm (3.9 inches)	66%	very high
September Weather	15°C (59°F)	71 mm (2.8 inches)	71%	high
October Weather	8°C (47°F)	143 mm (5.6 inches)	78%	moderate
November Weather	0°C (33°F)	119 mm (4.7 inches)	84%	moderate
December Weather	-5°C (23°F)	113 mm (4.5 inches)	81%	low