September Weather in Dover, United States

Last updated: June 24, 2025

In September, the average temperature in Dover, United States hovers around 20°C (68°F). However, expect fluctuations, with a minimum of 4°C (39°F) and a maximum of 34°C (93°F). During this time, precipitation amounts to around 107 mm (4.2 in), typically falling over 9 days. The average humidity during this month is a comfortable 77%, creating a pleasant atmosphere for both locals and visitors alike.

September Temperature in Dover

In September in Dover, the average temperature is 20°C (68°F). The maximum can reach 34°C (93°F), while the minimum can be as low as 4°C (39°F). Overall, this month offers a pleasant variety of temperatures, making it an excellent time for travelers to explore the region.

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

The chart illustrates September temperature patterns in Dover, showcasing daily minimum, maximum, and average temperatures. It highlights the typical range of temperatures throughout the month, providing insights into weather trends. In Dover, 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 4°C (39°F).

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

September Precipitation in Dover

In Dover in September, the precipitation amount is 107 mm (4.2 in), occurring over a span of 9 days.

September Precipitation Trends in Dover

The chart displays monthly precipitation patterns in Dover, 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 Dover, September typically receives around 107 mm (4.2 inches) of precipitation spread over approximately 9 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 Dover

In Dover in September, humidity is 77%. With an average temperature of 20°C (68°F), this humidity feels like a warm, sticky embrace, making it essential for travelers to stay hydrated and take breaks in shaded areas to avoid feeling sluggish in the heat.

September Average Humidity in Dover

This chart illustrates the average monthly humidity levels in Dover, 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 Dover is approximately 77%, 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 Dover

In Dover 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 Dover.

Maximum UV Index Levels in Dover for September

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

Data source: Dover 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 Dover Compares to Other Months

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

This table compares monthly weather conditions in Dover, showing how September’s temperature, precipitation, humidity, and UV index levels differ from those of other months.
	Temperature	Precipitation	Humidity	UV
January Weather	-1°C (31°F)	92 mm (3.6 inches)	88%	moderate
February Weather	1°C (34°F)	109 mm (4.3 inches)	88%	moderate
March Weather	5°C (42°F)	103 mm (4.1 inches)	87%	high
April Weather	11°C (51°F)	132 mm (5.2 inches)	87%	very high
May Weather	17°C (63°F)	121 mm (4.7 inches)	81%	very high
June Weather	21°C (71°F)	128 mm (5.0 inches)	83%	very high
July Weather	24°C (75°F)	120 mm (4.7 inches)	82%	very high
August Weather	23°C (73°F)	92 mm (3.6 inches)	76%	very high
September Weather	20°C (68°F)	107 mm (4.2 inches)	77%	very high
October Weather	14°C (57°F)	111 mm (4.4 inches)	82%	high
November Weather	5°C (42°F)	96 mm (3.8 inches)	89%	moderate
December Weather	2°C (36°F)	96 mm (3.8 inches)	86%	low