August Weather in Jamestown, Saint Helena, Ascension and Tristan da Cunha

Last updated: August 31, 2025

In August, the average temperature in Jamestown, Saint Helena, Ascension and Tristan da Cunha hovers around 20°C (68°F), providing a pleasant climate. Expect minimum temperatures of 18°C (66°F) and maximums reaching 21°C (71°F). During the month, precipitation is light, totaling about 14 mm (0.6 in) spread over just 3 days. The average humidity maintains a comfortable 76%, making it an inviting time to experience all that Jamestown has to offer.

August Temperature in Jamestown

In August in Jamestown, the average temperature is 20°C (68°F). The maximum can reach 21°C (71°F), and the minimum can be as low as 18°C (66°F). This mild climate makes it a perfect time for outdoor activities and exploration in Jamestown.

August Weather in Jamestown: Daily Temperature Highs, Lows, and Averages

The chart illustrates August temperature patterns in Jamestown, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Jamestown, August typically has an average temperature of 20°C (68°F), with highs reaching up to 21°C (71°F) and lows dropping to around 18°C (66°F).

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

August Precipitation in Jamestown

In Jamestown in August, the precipitation amount is 14 mm (0.6 in) accumulated over the course of 3 days.

August Precipitation Trends in Jamestown

The chart displays monthly precipitation patterns in Jamestown, with values for each month alongside August’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how August’s conditions compare to those of other months. In Jamestown, August typically receives around 14 mm (0.6 inches) of precipitation spread over approximately 3 days.

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

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Millimeters (mm) Inches (in)

August Humidity in Jamestown

In Jamestown in August, humidity is 76%. With an average temperature of 20°C (68°F), this humidity feels like a warm blanket wrapping around you, making outdoor exploration both exhilarating and slightly stifling, ideal for leisurely strolls but necessitating frequent breaks to hydrate and cool off.

August Average Humidity in Jamestown

This chart illustrates the average monthly humidity levels in Jamestown, with August’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In August, average humidity in Jamestown is approximately 76%, offering insight into how humid the weather typically is during this month.

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

August UV Index in Jamestown

In Jamestown in August, the maximum UV index reaches 10, which corresponds to a very high Exposure Category. With a time to burn of just 15 minutes, it's crucial to take precautions. For more detailed information, you can check the Hourly UV Index in Jamestown.

Maximum UV Index Levels in Jamestown for August

The chart shows the monthly maximum UV Index (UVI) for Jamestown in August, 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 August, the maximum UV index in Jamestown typically reaches 10, which falls under the very high exposure category.

Data source: Jamestown August 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 August Weather in Jamestown Compares to Other Months

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

This table compares monthly weather conditions in Jamestown, showing how August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	23°C (73°F)	10 mm (0.4 inches)	79%	extreme
February Weather	24°C (75°F)	12 mm (0.5 inches)	81%	extreme
March Weather	24°C (76°F)	16 mm (0.6 inches)	82%	extreme
April Weather	24°C (75°F)	14 mm (0.6 inches)	81%	extreme
May Weather	23°C (73°F)	12 mm (0.5 inches)	78%	very high
June Weather	22°C (71°F)	14 mm (0.5 inches)	74%	very high
July Weather	21°C (69°F)	12 mm (0.5 inches)	75%	very high
August Weather	20°C (68°F)	14 mm (0.6 inches)	76%	very high
September Weather	20°C (67°F)	13 mm (0.5 inches)	78%	extreme
October Weather	19°C (67°F)	11 mm (0.4 inches)	80%	extreme
November Weather	20°C (68°F)	10 mm (0.4 inches)	81%	extreme
December Weather	21°C (70°F)	10 mm (0.4 inches)	80%	extreme