January Weather in Thornhill, South Africa

Last updated: August 31, 2025

In Thornhill, South Africa, the average temperature in January is a pleasant 21°C (70°F). Expect a range where the minimum dips to 15°C (59°F), while the maximum can soar to 31°C (89°F). During this time, anticipate 28 mm (1.1 in) of precipitation spread over about 7 days, with a comfortable average humidity of 79%. Enjoy the balance of warmth and occasional rain on your travels!

January Temperature in Thornhill

In January in Thornhill, the average temperature is 21°C (70°F). The maximum can reach 31°C (89°F) and the minimum can be as low as 15°C (59°F). This makes it an ideal time to explore outdoor activities while enjoying comfortable weather.

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

The chart illustrates January temperature patterns in Thornhill, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Thornhill, January typically has an average temperature of 21°C (70°F), with highs reaching up to 31°C (89°F) and lows dropping to around 15°C (59°F).

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

January Precipitation in Thornhill

In Thornhill in January, the precipitation amount is 28 mm (1.1 in) over a period of 7 days.

January Precipitation Trends in Thornhill

The chart displays monthly precipitation patterns in Thornhill, 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 Thornhill, January typically receives around 28 mm (1.1 inches) of precipitation spread over approximately 7 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 Thornhill

In Thornhill in January humidity is 79%. With an average temperature of 21°C (70°F), this humidity feels like a warm embrace, making outdoor exploration a bit sticky but still enjoyable for travelers who appreciate the lush, vibrant atmosphere.

January Average Humidity in Thornhill

This chart illustrates the average monthly humidity levels in Thornhill, 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 Thornhill is approximately 79%, 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 Thornhill

In Thornhill in January, the maximum UV index is 14, which corresponds to an extreme Exposure Category. The time to burn is just 10 minutes, so it's crucial to take precautions. For the detailed hourly UV index in Thornhill, you can check here.

Maximum UV Index Levels in Thornhill for January

The chart shows the monthly maximum UV Index (UVI) for Thornhill 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 Thornhill typically reaches 14, which falls under the extreme exposure category.

Data source: Thornhill 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 Thornhill Compares to Other Months

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

This table compares monthly weather conditions in Thornhill, showing how January’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	21°C (70°F)	28 mm (1.1 inches)	79%	extreme
February Weather	21°C (70°F)	48 mm (1.9 inches)	81%	extreme
March Weather	20°C (69°F)	43 mm (1.7 inches)	83%	extreme
April Weather	18°C (65°F)	28 mm (1.1 inches)	80%	very high
May Weather	17°C (63°F)	31 mm (1.2 inches)	76%	moderate
June Weather	16°C (62°F)	19 mm (0.7 inches)	72%	moderate
July Weather	16°C (60°F)	33 mm (1.3 inches)	74%	moderate
August Weather	15°C (59°F)	53 mm (2.1 inches)	72%	high
September Weather	16°C (61°F)	42 mm (1.6 inches)	75%	very high
October Weather	17°C (63°F)	38 mm (1.5 inches)	76%	extreme
November Weather	18°C (65°F)	47 mm (1.9 inches)	76%	extreme
December Weather	20°C (67°F)	48 mm (1.9 inches)	78%	extreme