January Weather in Heidelberg, United States

Last updated: June 24, 2025

In Heidelberg, United States, the average temperature in January hovers around 10°C (50°F). During this month, temperatures can dip as low as -12°C (11°F) or rise to a warm 27°C (82°F). Expect 110 mm (4.3 in) of precipitation spread out over 8 days, contributing to an average humidity of a brisk 82%.

January Temperature in Heidelberg

In January in Heidelberg, the average temperature is 10°C (50°F). The maximum can reach 27°C (82°F) and the minimum can be as low as -12°C (11°F). Be prepared for a wide range of temperatures when traveling during this time, as it can range from chilly to pleasantly warm.

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

The chart illustrates January temperature patterns in Heidelberg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Heidelberg, January typically has an average temperature of 10°C (50°F), with highs reaching up to 27°C (82°F) and lows dropping to around -12°C (11°F).

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

January Precipitation in Heidelberg

In Heidelberg in January, the precipitation amount is 110 mm (4.3 in) over a period of 8 days.

January Precipitation Trends in Heidelberg

The chart displays monthly precipitation patterns in Heidelberg, 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 Heidelberg, January typically receives around 110 mm (4.3 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 Heidelberg

In Heidelberg in January, humidity is 82%. With an average temperature of 10°C (50°F), this humidity feels like a dense, heavy blanket wrapping around you, making every step feel sluggish and the air thick, which can make traveling quite uncomfortable.

January Average Humidity in Heidelberg

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

In Heidelberg in January, the maximum UV index reaches 4, which corresponds to a moderate Exposure Category. With a time to burn of 30 minutes, it’s important to take precautions to protect your skin. You can find more details in the Hourly UV Index in Heidelberg for better planning.

Maximum UV Index Levels in Heidelberg for January

The chart shows the monthly maximum UV Index (UVI) for Heidelberg 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 Heidelberg typically reaches 4, which falls under the moderate exposure category.

Data source: Heidelberg 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 Heidelberg Compares to Other Months

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

This table compares monthly weather conditions in Heidelberg, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	10°C (50°F)	110 mm (4.3 inches)	82%	moderate
February Weather	13°C (55°F)	140 mm (5.5 inches)	80%	high
March Weather	16°C (61°F)	121 mm (4.7 inches)	80%	very high
April Weather	18°C (65°F)	127 mm (5.0 inches)	78%	extreme
May Weather	23°C (74°F)	137 mm (5.4 inches)	73%	extreme
June Weather	26°C (79°F)	168 mm (6.6 inches)	71%	extreme
July Weather	27°C (81°F)	137 mm (5.4 inches)	79%	extreme
August Weather	27°C (81°F)	132 mm (5.2 inches)	78%	extreme
September Weather	26°C (78°F)	97 mm (3.8 inches)	80%	very high
October Weather	21°C (70°F)	99 mm (3.9 inches)	76%	very high
November Weather	13°C (56°F)	72 mm (2.8 inches)	83%	high
December Weather	11°C (53°F)	133 mm (5.3 inches)	87%	moderate