July Weather in Fairfax, United States

Last updated: June 24, 2025

The average temperature in Fairfax, United States during July is a warm 26°C (79°F). Temperatures can vary, with a minimum of 14°C (57°F) and a maximum reaching up to 38°C (100°F). Expect about 112 mm (4.4 in) of precipitation over 8 days, and be prepared for a humid atmosphere with an average humidity of 83%.

July Temperature in Fairfax

In July in Fairfax, the average temperature is 26°C (79°F), with maximums reaching up to 38°C (100°F) and minimums dropping as low as 14°C (57°F). This diverse temperature range makes it an ideal time for travelers to enjoy both warm days and cooler evenings.

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

The chart illustrates July 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, July typically has an average temperature of 26°C (79°F), with highs reaching up to 38°C (100°F) and lows dropping to around 14°C (57°F).

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

July Precipitation in Fairfax

In Fairfax in July, the total precipitation amount is 112 mm (4.4 in) spread over 8 days.

July Precipitation Trends in Fairfax

The chart displays monthly precipitation patterns in Fairfax, with values for each month alongside July’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how July’s conditions compare to those of other months. In Fairfax, July typically receives around 112 mm (4.4 inches) of precipitation spread over approximately 8 days.

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

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Millimeters (mm) Inches (in)

July Humidity in Fairfax

In Fairfax in July, humidity is 83%. With an average temperature of 26°C (79°F), this humidity feels like a heavy blanket enveloping you, making travel an exercise in endurance as the air clings to your skin and saps your energy.

July Average Humidity in Fairfax

This chart illustrates the average monthly humidity levels in Fairfax, with July’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In July, average humidity in Fairfax is approximately 83%, offering insight into how humid the weather typically is during this month.

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

July UV Index in Fairfax

In Fairfax in July, 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 Fairfax.

Maximum UV Index Levels in Fairfax for July

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

Data source: Fairfax July 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 July 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 July’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 July’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
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 Weather	7°C (44°F)	92 mm (3.6 inches)	73%	high
April Weather	11°C (53°F)	84 mm (3.3 inches)	74%	very high
May Weather	18°C (65°F)	157 mm (6.2 inches)	78%	very high
June Weather	25°C (77°F)	119 mm (4.7 inches)	82%	extreme
July Weather	26°C (79°F)	112 mm (4.4 inches)	83%	very high
August Weather	24°C (76°F)	120 mm (4.7 inches)	80%	very high
September Weather	22°C (71°F)	85 mm (3.3 inches)	75%	very high
October Weather	13°C (55°F)	129 mm (5.1 inches)	75%	high
November Weather	6°C (42°F)	37 mm (1.5 inches)	82%	moderate
December Weather	1°C (35°F)	32 mm (1.3 inches)	83%	moderate