December Weather in Swellendam, South Africa

Last updated: August 31, 2025

In December, Swellendam, South Africa, experiences a dynamic range of weather, highlighted by a striking maximum temperature soaring up to 40°C (105°F). The month presents an average temperature of 20°C (69°F), offering a delightful contrast to the minimum of 9°C (49°F) recorded during cooler nights. Though relatively dry with 25 mm (1.0 in) of precipitation over 6 days, humidity levels remain high at 79%, adding a warm tropical feel to the summer atmosphere. This combination of heat and occasional rain creates an inviting environment for both locals and visitors alike.

December Temperature in Swellendam

In Swellendam, South Africa, December marks a vibrant transition into summer, with temperatures reflecting the season's warmth. The month starts with a minimum low of 9°C (49°F), while the average high reaches a toasty 40°C (105°F), epitomizing the heat that characterizes this time of year. Generally, December's climate is characterized by mild nights and scorching days, following a trend of rising temperatures throughout the latter part of the year. With average temperatures hovering around 20°C (69°F), residents and visitors alike can enjoy the sun-drenched days, perfect for outdoor activities. As the year winds down, the warmth of December heralds the peak of summer, enticing adventurers to explore all that this picturesque region has to offer.

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

The chart illustrates December temperature patterns in Swellendam, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Swellendam, December typically has an average temperature of {2}°C ({3}°F), with highs reaching up to {4}°C ({5}°F) and lows dropping to around {6}°C ({7}°F).
JanFebMarAprMayJunJulAugSepOctNovDec717268635955545358636568
Data source: Temperature data for Swellendam 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 Swellendam

In December, Swellendam experiences a modest precipitation total of 25 mm (1.0 in), occurring over approximately 6 days. This slight dip in rainfall follows the significant 45 mm recorded in November, highlighting a seasonal transition as the year comes to a close. The December precipitation is representative of the region’s shift towards drier conditions, contrasting with the rainier months of late spring. Overall, as summer approaches, the trend indicates a gradual reduction in rainfall, yet the consistent frequency of rainy days keeps the landscape vibrant and lush during this time.

December Precipitation Trends in Swellendam

The chart displays monthly precipitation patterns in Swellendam, 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 Swellendam, December typically receives around {2} mm ({3} inches) of precipitation spread over approximately {4} days.
JanFebMarAprMayJunJulAugSepOctNovDec352238173023323628304525
Data source: Precipitation data for December generated using information from the Copernicus Climate Change Service.
Choose your preferred precipitation unit

December Humidity in Swellendam

In Swellendam, South Africa, December brings a humidity level of 79%, maintaining a consistent trend seen throughout the year. As the festive season kicks off, the humidity reflects a gradual rise from the cooler months, peaking in February at 82%. Interestingly, the level of humidity tends to fluctuate slightly, with March recording the highest average humidity at 83%, before gently tapering off through the autumn months. This creates a comfortable yet humid atmosphere as summer approaches, ensuring that visitors and residents alike feel the warmth of the season intertwined with the lush, vibrant environment characteristic of this beautiful region.

December Average Humidity in Swellendam

This chart illustrates the average monthly humidity levels in Swellendam, 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 Swellendam is approximately {2}%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec79%82%83%82%78%77%79%76%77%79%77%79%
Data source: Humidity data for December generated using information from the Copernicus Climate Change Service.

December UV Index in Swellendam

In December, Swellendam experiences a notably high UV Index of 14, classified as extreme. This trend continues from the preceding months of October and November, where the UV Index also reached extreme levels at 11 and 12, respectively. With a burn time of just 10 minutes, it's crucial for residents and visitors to take protective measures during peak daylight hours. This intensity contrasts sharply with the more moderate indices seen in the cooler months of May through July, highlighting the seasonal variations in sun exposure. As summer approaches, the urgency for sun safety becomes increasingly evident. For more detailed information, explore the Swellendam UV Index.

Maximum UV Index Levels in Swellendam for December

The chart shows the monthly maximum UV Index (UVI) for Swellendam 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 Swellendam typically reaches {2}, which falls under the {3} exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec141311854469111214
Data source: Swellendam 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.

December Sunshine in Swellendam

December in Swellendam, South Africa, shines as a beacon of sunshine, boasting 409 hours of glorious sunlight, the highest of the year. This month represents a significant crescendo in the annual cycle of brightness, following a steady climb from 381 hours in November. As the days lengthen and temperatures rise, visitors and locals alike can revel in the vibrant outdoor activities that the ample sunshine encourages. This upward trend is a reminiscent farewell to the year, with December illuminating the beautiful landscape and enhancing the town's charm, making it an ideal time for exploration and enjoyment.

Monthly Sunshine Duration in Swellendam: December Highlighted

The December sunshine duration represents the total number of hours Swellendam experiences direct sunlight during the month of December, excluding cloudy or obstructed periods. This chart compares the sunshine duration of December with the other months of the year.
JanFebMarAprMayJunJulAugSepOctNovDec321h350h348h308h292h276h293h309h324h362h381h409h
Data source: Swellendam December Sunshine duration data generated using information from the Copernicus Climate Change Service.

Chance of Sun in Swellendam During December

In Swellendam, South Africa, the likelihood of sunny weather experiences a notable decline as December rolls in, reaching a modest 36% chance of sun. This dip marks a clear contrast to the more sunlit months earlier in the year, such as January and February, which boast a robust 66% chance. Following a gradual decrease from 66% in June and July to 45% in November, December signifies the lowest probability of sunshine in the yearly cycle, hinting at the approach of the wetter summer season. Consequently, those planning outdoor activities during this month might want to prepare for a mix of overcast skies alongside the occasional burst of sun.

Percentage of Sunny Days in December in Swellendam

The chart illustrates the percentage of sunny days in Swellendam throughout the year, with December highlighted. It highlights the variation in sunshine across each month and provides an overview of the typical frequency of sunny days, offering insights into how often Swellendam experiences clear skies throughout the year.
JanFebMarAprMayJunJulAugSepOctNovDec66%66%52%48%57%66%67%58%50%49%45%36%
Data source: Swellendam December chance of sun data, generated using information from the Copernicus Climate Change Service.

Daylight Hours in Swellendam in December

In Swellendam, South Africa, December shines brightly with an impressive 14 hours of daylight, marking it as one of the sunniest months of the year. This month mirrors the daylight duration of January, both showcasing the peak of summer when the days are long and vibrant. From March to May, daylight gradually diminishes, dipping to 10 hours in May, as the seasons shift towards winter. However, as spring arrives in August and September, daylight begins to increase once again, ultimately leading back to the radiant 14 hours seen in December. This cyclical trend highlights the region’s unique climate, where long summer days invite outdoor adventures and vibrant sunsets.

Average Daylight Hours in Swellendam for December

The chart illustrates the variation in daylight duration in Swellendam throughout the year, with December highlighted. It shows the monthly changes in daylight hours, calculated by summing the hours between sunrise and sunset.
JanFebMarAprMayJunJulAugSepOctNovDec14h 6m13h 17m12h 14m11h 11m10h 19m9h 54m10h 7m10h 53m11h 53m12h 56m13h 52m14h 21m
Data source: Swellendam daylight hours, calculated by summing the hours between sunrise and sunset for each day.

December Winds in Swellendam

In December, Swellendam experiences a gentle breeze with an average wind speed of 3.1 m/s (7 mph), marking a slight increase from the calm winds of the preceding months. This uptick hints at a transition as summer approaches, providing a refreshing contrast to the warmer temperatures typical of the season. Notably, the average wind speeds in December mirror those of January and November, suggesting a trend of consistent breeziness during this time of year. As the winds dance through the charming landscapes of Swellendam, they offer an invigorating backdrop to the warm, sunlit days that characterize the summer months in this picturesque South African town.

Average December Wind Speed in Swellendam

The chart displays monthly wind speed patterns in Swellendam, with values for each month shown alongside December's data, which is highlighted for easy comparison. It illustrates the average wind speed, offering insights into how December's wind conditions compare to the rest of the year.
JanFebMarAprMayJunJulAugSepOctNovDec3.32.92.72.22.22.52.52.22.53.03.03.1 m/s
Data source: Swellendam December wind data, generated using information from the Copernicus Climate Change Service.

How December Weather in Swellendam Compares to Other Months

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

December and January weather share some similarities, but there are notable differences as well. In December, temperatures range from a minimum of 9°C (49°F) to a maximum of 40°C (105°F), with an average of 20°C (69°F) and only 25 mm (1.0 in) of precipitation over six days, while humidity sits at 79%. In contrast, January offers slightly warmer conditions, featuring a minimum of 11°C (52°F) and a maximum of 41°C (107°F), with an average temperature of 22°C (72°F). Precipitation increases to 35 mm (1.4 in) across the same six days, maintaining the humidity at 79%. For more detailed information, check out Swellendam weather in January.

December and February present similar weather patterns, characterized by warm temperatures and moderate precipitation. In December, temperatures range from a minimum of 9°C (49°F) to a maximum of 40°C (105°F), with an average of 20°C (69°F). The month experiences about 25 mm (1.0 in) of rainfall over six days, accompanied by a humidity level of 79%. Conversely, February sees a slight increase in temperatures, with a minimum of 11°C (52°F) and an average of 22°C (72°F), while the max temperature remains nearly identical at 40°C (104°F). Precipitation decreases to 22 mm (0.9 in), still over six days, and humidity rises slightly to 82%. For more specific details, you can check out Swellendam weather in February.

In December, temperatures typically range from a minimum of 9°C (49°F) to a maximum of 40°C (105°F), with an average of 20°C (69°F). The month receives about 25 mm (1.0 in) of rain over approximately 6 days, while humidity averages around 79%. In comparison, March sees slightly cooler temperatures, with a minimum of 8°C (47°F) and a maximum of 36°C (98°F), yet the average remains the same at 20°C (69°F). Precipitation increases to about 38 mm (1.5 in) over 7 days, with humidity rising marginally to 83%. Overall, March is characterized by a bit more rainfall and higher humidity compared to December. For more detailed insights, check out Swellendam weather in March.

December and April both showcase relatively warm weather, but with some notable differences. December has a wider temperature range, with a minimum of 9°C (49°F) and a maximum of 40°C (105°F), resulting in an average temperature of 20°C (69°F). In contrast, April is slightly cooler, with temperatures ranging from a minimum of 6°C (43°F) to a maximum of 38°C (101°F), averaging 17°C (64°F). Precipitation is more frequent in December, with 25 mm (1.0 in) falling over 6 days, compared to April's 17 mm (0.7 in) over just 4 days. Both months are characterized by high humidity, with December at 79% and April slightly higher at 82%. For more detailed insights on April weather, check out Swellendam weather in April.

December and May present contrasting weather patterns. In December, temperatures are notably warmer, with a minimum of 9°C (49°F) and highs reaching up to 40°C (105°F), resulting in an average temperature of 20°C (69°F). Meanwhile, May experiences cooler conditions, with temperatures ranging from a low of 3°C (38°F) to a high of 33°C (91°F) and an average of 15°C (60°F). Precipitation is slightly higher in May at 29 mm (1.2 in) over 4 days compared to December's 25 mm (1.0 in) over 6 days. The humidity remains fairly consistent, with December recording 79% and May slightly lower at 78%. For a deeper look at May's weather, check out Swellendam weather in May.

In December, the weather is significantly warmer, with temperatures ranging from a minimum of 9°C (49°F) to a sultry maximum of 40°C (105°F), while average temperatures hover around 20°C (69°F). The month experiences an average of 25 mm (1.0 in) of precipitation over about six days, combined with a humidity level of 79%. In contrast, June presents much cooler conditions, with temperatures ranging from a chilly 0°C (32°F) to a comfortable maximum of 29°C (85°F) and an average of 13°C (56°F). The month sees slightly less precipitation at 23 mm (0.9 in) over five days, with humidity levels at 77%. For a more detailed insight into June weather, you can explore Swellendam weather in June.

When comparing the weather in December and July, a stark contrast emerges. December boasts much warmer temperatures, with a minimum of 9°C (49°F) and a maximum soaring up to 40°C (105°F), while July experiences much cooler averages, ranging from a minimum of 0°C (32°F) to a maximum of 31°C (88°F). Precipitation levels are fairly similar, with December receiving 25 mm (1.0 in) and July slightly higher at 32 mm (1.3 in), both across 6 days. Humidity remains quite consistent, with December at 79% and July a touch lower at 78%. To explore more about the weather specifics during July, check out Swellendam weather in July.

In comparing the weather of December and August, it is clear that December offers a much warmer climate, with average temperatures peaking at 20°C (69°F) compared to August's average of 12°C (54°F). December sees maximum temperatures soaring up to 40°C (105°F), while August's hottest day reaches only 31°C (88°F). Interestingly, both months experience similar precipitation levels, with December receiving 25 mm and August slightly higher at 36 mm, both spread over around six days. Humidity levels are comparable as well, with December at 79% and August at 76%. For those looking for more detailed insights, you can check out the Swellendam weather in August.

In December, the weather is significantly warmer, with average temperatures ranging from a minimum of 9°C (49°F) to a maximum of 40°C (105°F), compared to September's milder range of 2°C (35°F) to 37°C (99°F). Despite both months experiencing low precipitation—25 mm (1.0 in) in December and 28 mm (1.1 in) in September—the humidity remains relatively high in both months, with December at 79% and September at 77%. The slightly higher number of rainy days in December, at 6 compared to September's 5, indicates that the end of the year may feel a bit more damp. For more details on September weather, you can explore Swellendam weather in September.

When comparing the weather in December to that in October, several differences can be noted. December experiences higher temperatures, with a minimum of 9°C and an average of 20°C, while October's temperatures range from a minimum of 4°C and an average of 17°C. Both months show similar maximum temperatures, with December reaching up to 40°C and October slightly lower at 39°C. Precipitation also varies slightly; December sees about 25 mm over 6 days, compared to October's 30 mm over 7 days. Interestingly, both months maintain the same humidity level of 79%. For a closer look at October's specific weather patterns, you can visit Swellendam weather in October.

In comparing the weather between December and November, December enjoys slightly warmer temperatures, with an average of 20°C (69°F) compared to November's 18°C (66°F). While both months experience a similar number of rainy days at six, December sees less precipitation overall, with 25 mm (1.0 in) versus November's 45 mm (1.8 in). Humidity levels are relatively close, with December at 79% and November at 77%, indicating that the air remains quite moist in both months. For a closer look at November's climate, you can visit Swellendam weather in November.

Compare Swellendam's Climate with Cities Worldwide

Conclusion: What to Expect From December Weather in Swellendam

As December unfolds in Swellendam, the weather transforms into a vibrant blend of warm temperatures and increased humidity, offering a distinctive experience compared to the cooler months that precede it. With longer, sun-drenched days, visitors can expect an enchanting mix of sunshine and rain, as precipitation occurs on about six days across the month. This balance creates a lush landscape, making December a particularly appealing time for outdoor activities and exploration. For more detailed insights into the month’s conditions and how they compare to other times of the year, check out the insightful resource on Swellendam Climate.