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August Weather in Fairfax, United States

Last updated: June 24, 2025

The average temperature in Fairfax, United States during August is a pleasant 24°C (76°F). Expect a range where the minimum can dip to 11°C (52°F), while the maximum might soar to 36°C (97°F). However, be prepared for some rain, as the precipitation amount is around 120 mm (4.7 in) spread over 10 days. With an average humidity of 80%, it's a month where the air can feel quite moist!

August Temperature in Fairfax

In August in Fairfax, the average temperature is 24°C (76°F). Maximum temperatures can reach 36°C (97°F), while minimums can dip as low as 11°C (52°F). This diverse temperature range makes Fairfax an ideal destination for travelers seeking both warm days and cooler evenings.

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

The chart illustrates August temperature patterns in Fairfax, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Fairfax, August typically has an average temperature of 24°C (76°F), with highs reaching up to 36°C (97°F) and lows dropping to around 11°C (52°F).
JanFebMarAprMayJunJulAugSepOctNovDec282944526577797571554234
Data source: Temperature data for Fairfax 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.

August Precipitation in Fairfax

In Fairfax in August, the precipitation amount is 120 mm (4.7 in) spread over a duration of 10 days.

August Precipitation Trends in Fairfax

The chart displays monthly precipitation patterns in Fairfax, 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 Fairfax, August typically receives around 120 mm (4.7 inches) of precipitation spread over approximately 10 days.
JanFebMarAprMayJunJulAugSepOctNovDec36329284157119112120851293732
Data source: Precipitation data for August generated using information from the Copernicus Climate Change Service.
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August Humidity in Fairfax

In Fairfax in August humidity is 80%. With an average temperature of 24°C (76°F), this humidity feels like a warm, sticky embrace that can make exploring outdoors quite draining, so it's essential to stay hydrated and take breaks in the shade while traveling.

August Average Humidity in Fairfax

This chart illustrates the average monthly humidity levels in Fairfax, 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 Fairfax is approximately 80%, offering insight into how humid the weather typically is during this month.
JanFebMarAprMayJunJulAugSepOctNovDec76%80%73%75%78%82%83%81%75%75%82%83%
Data source: Humidity data for August generated using information from the Copernicus Climate Change Service.

August UV Index in Fairfax

In Fairfax in August, the maximum UV index is 9, which corresponds to a very high Exposure Category. The time to burn is just 15 minutes, so it's essential to take precautions. For detailed information, you can check the Hourly UV Index in Fairfax.

Maximum UV Index Levels in Fairfax for August

The chart shows the monthly maximum UV Index (UVI) for Fairfax 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 Fairfax typically reaches 9, which falls under the very high exposure category.
JanFebMarAprMayJunJulAugSepOctNovDec356910111098643
Data source: Fairfax 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 Fairfax Compares to Other Months

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

This table compares monthly weather conditions in Fairfax, showing how August’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
 TemperaturePrecipitationHumidityUV
January Weather-2°C (28°F)36 mm (1.4 inches)76%moderate
February Weather-2°C (29°F)32 mm (1.2 inches)80%moderate
March Weather7°C (44°F)92 mm (3.6 inches)73%high
April Weather11°C (53°F)84 mm (3.3 inches)74%very high
May Weather18°C (65°F)157 mm (6.2 inches)78%very high
June Weather25°C (77°F)119 mm (4.7 inches)82%extreme
July Weather26°C (79°F)112 mm (4.4 inches)83%very high
August Weather24°C (76°F)120 mm (4.7 inches)80%very high
September Weather22°C (71°F)85 mm (3.3 inches)75%very high
October Weather13°C (55°F)129 mm (5.1 inches)75%high
November Weather6°C (42°F)37 mm (1.5 inches)82%moderate
December Weather1°C (35°F)32 mm (1.3 inches)83%moderate

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