September Weather in Wilmington, United States

Last updated: June 24, 2025

The average temperature in Wilmington, United States during September is a pleasant 21°C (69°F). Expect temperatures to range from a cool 5°C (42°F) to a warm 34°C (93°F). During this month, the precipitation amount averages 84 mm (3.3 in), typically spread over 7 days, contributing to an average humidity of 73%. Plan accordingly to enjoy all that this destination has to offer!

September Temperature in Wilmington

In September in Wilmington, the average temperature is 21°C (69°F). Maximums can reach 34°C (93°F), and minimums can be as low as 5°C (42°F). This makes Wilmington an ideal destination for travelers looking for mild weather with the possibility of warmer or cooler days.

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

The chart illustrates September temperature patterns in Wilmington, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Wilmington, September typically has an average temperature of 21°C (69°F), with highs reaching up to 34°C (93°F) and lows dropping to around 5°C (42°F).

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

September Precipitation in Wilmington

In Wilmington in September, the total precipitation amount is 84 mm (3.3 in) distributed over a span of 7 days.

September Precipitation Trends in Wilmington

The chart displays monthly precipitation patterns in Wilmington, 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 Wilmington, September typically receives around 84 mm (3.3 inches) of precipitation spread over approximately 7 days.

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

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Millimeters (mm) Inches (in)

September Humidity in Wilmington

In Wilmington in September, humidity is 73%. With an average temperature of 21°C (69°F), this humidity feels like a warm, sticky embrace, making outdoor activities somewhat stifling and travel a bit more challenging, as the air is dense and can leave you feeling fatigued more quickly.

September Average Humidity in Wilmington

This chart illustrates the average monthly humidity levels in Wilmington, 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 Wilmington is approximately 73%, 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 Wilmington

In Wilmington 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 Wilmington.

Maximum UV Index Levels in Wilmington for September

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

Data source: Wilmington 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 Wilmington Compares to Other Months

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

This table compares monthly weather conditions in Wilmington, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	0°C (32°F)	79 mm (3.1 inches)	88%	moderate
February Weather	2°C (35°F)	106 mm (4.2 inches)	88%	moderate
March Weather	6°C (44°F)	128 mm (5.0 inches)	87%	high
April Weather	11°C (53°F)	120 mm (4.7 inches)	85%	very high
May Weather	18°C (65°F)	124 mm (4.9 inches)	81%	very high
June Weather	22°C (72°F)	129 mm (5.1 inches)	82%	very high
July Weather	24°C (76°F)	133 mm (5.2 inches)	81%	very high
August Weather	23°C (74°F)	86 mm (3.4 inches)	73%	very high
September Weather	21°C (69°F)	84 mm (3.3 inches)	73%	very high
October Weather	14°C (58°F)	97 mm (3.8 inches)	78%	high
November Weather	6°C (43°F)	96 mm (3.8 inches)	89%	moderate
December Weather	3°C (37°F)	108 mm (4.2 inches)	87%	moderate