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December Weather in Koster, South Africa

Last updated: August 31, 2025

In December, the average temperature in Koster, South Africa is a pleasant 23°C (73°F), making it an ideal time to explore. However, be prepared for temperature fluctuations, as it can dip to a minimum of 12°C (55°F) or soar to a sizzling 38°C (100°F). Expect 120 mm (4.7 in) of precipitation spread over 14 days, with an average humidity level of 64%, adding to the season's unique charm.

December Temperature in Koster

In December, in Koster, the average temperature is 23°C (73°F), with maximums reaching up to 38°C (100°F) and minimums dropping as low as 12°C (55°F). This makes Koster an ideal travel destination for those who enjoy warm weather but should be prepared for a range of temperatures.

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

The chart illustrates December temperature patterns in Koster, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Koster, December typically has an average temperature of 23°C (73°F), with highs reaching up to 38°C (100°F) and lows dropping to around 12°C (55°F).
JanFebMarAprMayJunJulAugSepOctNovDec737270655954546068717373
Data source: Temperature data for Koster generated using information from the Copernicus Climate Change Service.
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The average of daily temperatures (24 hours) calculated across all days in the month.

December Precipitation in Koster

In Koster in December, the precipitation amount is 120 mm (4.7 in) over the course of 14 days.

December Precipitation Trends in Koster

The chart displays monthly precipitation patterns in Koster, 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 Koster, December typically receives around 120 mm (4.7 inches) of precipitation spread over approximately 14 days.
JanFebMarAprMayJunJulAugSepOctNovDec1061285343952154868121
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
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December Humidity in Koster

In Koster in December, humidity is 64%. With an average temperature of 23°C (73°F), this humidity feels like a warm embrace, making travel quite comfortable yet slightly sticky, urging travelers to enjoy leisurely activities early in the day or seek shade during peak hours.

December Average Humidity in Koster

This chart illustrates the average monthly humidity levels in Koster, 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 Koster is approximately 64%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec66%66%67%61%56%56%55%45%49%47%53%64%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Koster

In Koster 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 Koster.

Maximum UV Index Levels in Koster for December

The chart shows the monthly maximum UV Index (UVI) for Koster 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 Koster typically reaches 16, which falls under the extreme exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec16151311766911131416
Data source: Koster 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 Koster Compares to Other Months

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

This table compares monthly weather conditions in Koster, showing how December’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather23°C (74°F)106 mm (4.2 inches)66%extreme
February Weather22°C (72°F)128 mm (5.0 inches)66%extreme
March Weather21°C (70°F)53 mm (2.1 inches)67%extreme
April Weather18°C (65°F)43 mm (1.7 inches)61%extreme
May Weather15°C (59°F)9 mm (0.4 inches)56%high
June Weather12°C (55°F)5 mm (0.2 inches)56%high
July Weather12°C (54°F)2 mm (0.1 inches)55%high
August Weather16°C (61°F)1 mm (0.1 inches)45%very high
September Weather20°C (68°F)5 mm (0.2 inches)49%extreme
October Weather21°C (71°F)47 mm (1.9 inches)47%extreme
November Weather23°C (73°F)67 mm (2.7 inches)53%extreme
December Weather23°C (73°F)120 mm (4.7 inches)64%extreme

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