Dover
Delaware, USA
Long-term weather forecast
Long-term weather forecast

September weather forecast and climate
Dover, DE

The public Archives building in Dover, Delaware, between two large trees
The public Archives building in Dover, Delaware, between two large trees
September, the first month of the autumn, in Dover, is also a moderately hot month, with average temperature fluctuating between 63°F (17.2°C) and 76.3°F (24.6°C).

Temperature

In September, the average high-temperature slightly decreases, from 81.9°F (27.7°C) in August, to a still warm 76.3°F (24.6°C). In September, in Dover, the average low-temperature is 63°F (17.2°C).

Humidity

In Dover, the average relative humidity in September is 78%.

Rainfall

In September, the rain falls for 12.9 days. Throughout September, 1.89" (48mm) of precipitation is accumulated. Throughout the year, in Dover, there are 152.3 rainfall days, and 26.3" (668mm) of precipitation is accumulated.

Snowfall

April through November are months without snowfall.

Daylight

In September, the average length of the day is 12.4h.

Sunshine

The average sunshine is 9.2h.

UV index

The average daily maximum UV index in Dover is 5. A UV Index reading of 3 to 5 represents a medium health hazard from unprotected exposure to the Sun's UV rays for the ordinary person.
Note: The average daily UV index of 5 in September transform into the following instructions:
Take precautions - Protection against sun damage is advised. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.

What is the temperature in September in Dover?

In September, in Dover, the average high-temperature is 76.3°F (24.6°C), and the average low-temperature is 63°F (17.2°C).

What is the average humidity in September in Dover?

In September, the average relative humidity in Dover is 78%.

How much does it rain in Dover in September?

In September, in Dover, the rain falls for 12.9 days. Throughout September, 1.89" (48mm) of precipitation is accumulated.

When it does not snow in Dover?

In Dover, Delaware, snow does not fall in April through November.

How many hours of daylight does Dover have in September?

In Dover, Delaware, the average length of the day in September is 12.4h.

How many hours of sunshine does Dover have in September?

In September, the average sunshine in Dover is 9.2h.

What is the UV index intensity in September in Dover?

In September, the average daily maximum UV index is 5. A UV Index estimate of 3 to 5 represents a medium hazard to health from the exposure to the Sun's UV radiation.
Average temperature in September - Dover, DE
  • Average high temperature in September: 24.6°C

The warmest month (with the highest average high temperature) is July (29°C).
The month with the lowest average high temperature is January (4.3°C).

  • Average low temperature in September: 17.2°C

The month with the highest average low temperature is July (21.1°C).
The coldest month (with the lowest average low temperature) is January (-1.8°C).

Average humidity in September - Dover, DE
  • Average humidity in September: 78%

The month with the highest relative humidity is May (79%).
Months with the lowest relative humidity are January, March, April and November (74%).

Average rainfall in September - Dover, DE
  • Average rainfall in September: 48mm

The wettest month (with the highest rainfall) is August (80mm).
The driest month (with the lowest rainfall) is January (37mm).

Average rainfall days in September - Dover, DE
  • Average rainfall days in September: 12.9 days

The month with the highest number of rainy days is July (17.6 days).
The month with the lowest number of rainy days is November (8.1 days).

Average snowfall in September - Dover, DE
  • Average snowfall in September: 0mm

The month with the highest snowfall is January (42mm).
Months with the lowest snowfall are April, May, June, July, August, September, October and November (0mm).

Average snowfall days in September - Dover, DE
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (3.5 days).
Months with the lowest number of snowfall days are April, May, June, July, August, September, October and November (0 days).

Average daylight in September / Average sunshine in September - Dover, DE
  • Average daylight in September: 12.4h

The month with the longest days is June (Average daylight: 14.9h).
The month with shortest days is December (Average daylight: 9.5h).

  • Average sunshine in September: 9.2h

The month with most sunshine is July (Average sunshine: 10.8h).
The month with least sunshine is February (Average sunshine: 5h).

Average UV index in September - Dover, DE
  • Average UV index in September: 5

Months with the highest UV index are May, June, July and August (UV index 6).
Months with the lowest UV index are January and December (UV index 2).