December Weather in Heidelberg, South Africa

Last updated: August 31, 2025

In December, the average temperature in Heidelberg, South Africa is a pleasant 20°C (69°F). However, temperatures can vary, dipping to a minimum of 10°C (50°F) and rising to a maximum of 34°C (93°F). Expect about 156 mm (6.1 in) of precipitation over 18 days, contributing to an average humidity of 81%. Plan accordingly to enjoy this climate!

December Temperature in Heidelberg

In December in Heidelberg, the average temperature is 20°C (69°F). Maximum temperatures can reach up to 34°C (93°F), while the minimum can drop as low as 10°C (50°F). This makes it an ideal time for travelers to enjoy outdoor activities while being prepared for varying temperatures.

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

The chart illustrates December 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, December typically has an average temperature of 20°C (69°F), with highs reaching up to 34°C (93°F) and lows dropping to around 10°C (50°F).

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

December Precipitation in Heidelberg

In Heidelberg in December, the total precipitation amount is 156 mm (6.1 in), occurring over a span of 18 days.

December Precipitation Trends in Heidelberg

The chart displays monthly precipitation patterns in Heidelberg, with values for each month alongside December’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how December’s conditions compare to those of other months. In Heidelberg, December typically receives around 156 mm (6.1 inches) of precipitation spread over approximately 18 days.

Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.

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Millimeters (mm) Inches (in)

December Humidity in Heidelberg

In Heidelberg in December, humidity is 81%. With an average temperature of 20°C (69°F), this humidity feels like a thick blanket embracing you, making travel a bit uncomfortable and sticky.

December Average Humidity in Heidelberg

This chart illustrates the average monthly humidity levels in Heidelberg, with December’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In December, average humidity in Heidelberg is approximately 81%, offering insight into how humid the weather typically is during this month.

Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Heidelberg

In Heidelberg in December, the maximum UV index is 16, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, making it crucial to take protective measures. For detailed information, you can refer to the Hourly UV Index in Heidelberg.

Maximum UV Index Levels in Heidelberg for December

The chart shows the monthly maximum UV Index (UVI) for Heidelberg in December, 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 December, the maximum UV index in Heidelberg typically reaches 16, which falls under the extreme exposure category.

Data source: Heidelberg December 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 December 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 December’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 December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	21°C (69°F)	121 mm (4.8 inches)	79%	extreme
February Weather	20°C (69°F)	126 mm (5.0 inches)	77%	extreme
March Weather	19°C (67°F)	72 mm (2.8 inches)	77%	extreme
April Weather	16°C (62°F)	60 mm (2.4 inches)	81%	very high
May Weather	13°C (56°F)	14 mm (0.5 inches)	82%	high
June Weather	11°C (51°F)	5 mm (0.2 inches)	73%	high
July Weather	10°C (51°F)	2 mm (0.1 inches)	71%	high
August Weather	14°C (57°F)	2 mm (0.1 inches)	68%	very high
September Weather	18°C (64°F)	9 mm (0.4 inches)	74%	extreme
October Weather	19°C (66°F)	66 mm (2.6 inches)	74%	extreme
November Weather	20°C (69°F)	106 mm (4.2 inches)	82%	extreme
December Weather	20°C (69°F)	156 mm (6.1 inches)	81%	extreme