July Weather in Fairfax, United States

Last updated: June 24, 2025

In Fairfax, United States, the average temperature in July is a pleasant 23°C (74°F). However, temperatures can fluctuate widely, reaching a minimum of 12°C (53°F) and soaring up to 36°C (97°F). Visitors can expect 123 mm (4.8 in) of precipitation spread over 9 days, accompanied by a relatively high average humidity of 81%.

July Temperature in Fairfax

In July in Fairfax, the average temperature is 23°C (74°F). The maximum can reach 36°C (97°F), while the minimum can drop as low as 12°C (53°F). Be prepared for warm days and cooler evenings when planning your travels.

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 23°C (74°F), with highs reaching up to 36°C (97°F) and lows dropping to around 12°C (53°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 precipitation amount is 123 mm (4.8 in) over the course of 9 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 123 mm (4.8 inches) of precipitation spread over approximately 9 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 81%. With an average temperature of 23°C (74°F), this humidity feels like a warm, heavy blanket draped over your skin, making travel feel a bit more sluggish and requiring plenty of water breaks to stay comfortable.

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 81%, 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 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 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 9, 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	-9°C (16°F)	26 mm (1.0 inches)	87%	moderate
February Weather	-9°C (16°F)	27 mm (1.1 inches)	90%	moderate
March Weather	0°C (33°F)	62 mm (2.5 inches)	85%	moderate
April Weather	6°C (43°F)	80 mm (3.1 inches)	84%	very high
May Weather	15°C (60°F)	124 mm (4.9 inches)	78%	very high
June Weather	22°C (72°F)	106 mm (4.2 inches)	80%	very high
July Weather	23°C (74°F)	123 mm (4.8 inches)	81%	very high
August Weather	21°C (71°F)	124 mm (4.9 inches)	81%	very high
September Weather	18°C (65°F)	118 mm (4.6 inches)	81%	very high
October Weather	9°C (48°F)	97 mm (3.8 inches)	84%	moderate
November Weather	1°C (34°F)	30 mm (1.2 inches)	88%	moderate
December Weather	-4°C (24°F)	40 mm (1.6 inches)	84%	low