September Weather in Williamsburg, United States

Last updated: June 24, 2025

In Williamsburg, United States, the average temperature in September hovers around 20°C (68°F), with a range from a cool 3°C (38°F) to a warm 34°C (93°F). Expect about 123 mm (4.8 in) of precipitation spread over 9 days, contributing to an average humidity of 78%. Whether you're planning outdoor adventures or cozy indoor activities, the weather is sure to offer a unique experience!

September Temperature in Williamsburg

In September in Williamsburg, the average temperature is 20°C (68°F). Maximums can reach 34°C (93°F), and minimums can be as low as 3°C (38°F). Be prepared for a range of weather conditions during your travels!

September Weather in Williamsburg: Daily Temperature Highs, Lows, and Averages

The chart illustrates September temperature patterns in Williamsburg, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Williamsburg, September typically has an average temperature of 20°C (68°F), with highs reaching up to 34°C (93°F) and lows dropping to around 3°C (38°F).

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

September Precipitation in Williamsburg

In Williamsburg in September, the precipitation amount is 123 mm (4.8 in) over the course of 9 days.

September Precipitation Trends in Williamsburg

The chart displays monthly precipitation patterns in Williamsburg, with values for each month alongside September’s data, which is highlighted for easy comparison. It shows the amount of precipitation, providing insights into how September’s conditions compare to those of other months. In Williamsburg, September typically receives around 123 mm (4.8 inches) of precipitation spread over approximately 9 days.

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

Choose your preferred precipitation unit

Millimeters (mm) Inches (in)

September Humidity in Williamsburg

In Williamsburg in September humidity is 78%. With an average temperature of 20°C (68°F), this humidity feels like a warm, enveloping blanket that makes exploring the sights a bit sticky, so travelers should stay hydrated and take frequent breaks in the shade.

September Average Humidity in Williamsburg

This chart illustrates the average monthly humidity levels in Williamsburg, with September’s data highlighted for easy comparison. It shows the fluctuation in humidity throughout the year, helping you understand how conditions vary by season. In September, average humidity in Williamsburg is approximately 78%, offering insight into how humid the weather typically is during this month.

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

September UV Index in Williamsburg

In Williamsburg in September, the maximum UV index is 8, which corresponds to a very high Exposure Category. This means that the time to burn is only 15 minutes. For more detailed information, you can refer to the Hourly UV Index in Williamsburg.

Maximum UV Index Levels in Williamsburg for September

The chart shows the monthly maximum UV Index (UVI) for Williamsburg in September, 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 September, the maximum UV index in Williamsburg typically reaches 8, which falls under the very high exposure category.

Data source: Williamsburg September 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 September Weather in Williamsburg Compares to Other Months

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

This table compares monthly weather conditions in Williamsburg, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-6°C (22°F)	48 mm (1.9 inches)	81%	moderate
February Weather	-5°C (24°F)	54 mm (2.1 inches)	81%	moderate
March Weather	4°C (39°F)	78 mm (3.1 inches)	81%	high
April Weather	9°C (49°F)	84 mm (3.3 inches)	82%	very high
May Weather	17°C (62°F)	158 mm (6.2 inches)	78%	very high
June Weather	23°C (74°F)	136 mm (5.4 inches)	81%	extreme
July Weather	24°C (76°F)	79 mm (3.1 inches)	79%	very high
August Weather	23°C (73°F)	64 mm (2.5 inches)	77%	very high
September Weather	20°C (68°F)	123 mm (4.8 inches)	78%	very high
October Weather	11°C (53°F)	137 mm (5.4 inches)	78%	high
November Weather	3°C (38°F)	49 mm (1.9 inches)	87%	moderate
December Weather	-1°C (31°F)	43 mm (1.7 inches)	84%	moderate