Delaware weather in September 2025
Delaware weather in September 2025
Day
25 °C
Night
15 °C
Sea
22 °C
Precipitation
92 mm
in month
Rainy days
8 days
in month
Daylight
12 hours
average
Sunshine
7 hours
average
Humidity
74 %
Day
25 °C
Night
15 °C
Sea
22 °C
Precipitation
92 mm
in month
Rainy days
8 days
in month
Daylight
12 hours
average
Sunshine
7 hours
average
Humidity
74 %
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Weather overview and FAQs
Weather overview
In Delaware in September, the average air temperature ranges from 25 °C (78 °F) during the day to 15 °C (59 °F) at night. There are 8 days of rain on average, where the rainfall is 92 mm (3.62 in).
Are there good conditions to visit in September in Delaware?
There are good conditions for visiting in Delaware in September. The temperature during the day will be nice 25 °C (78 °F). You can expect just 8 days of rain during the month, taking an umbrella is not necessary. A sea temperature of 22 °C (71 °F) can seem colder to some, but others will call it refreshing. The temperature of 15 °C (59 °F) at night may make it better to dine inside or to put on more clothes for a dinner outside.
What is the temperature in Delaware during the day in September?
In September in Delaware, the average daily temperatures will be 25 °C (78 °F). The ideal temperature for enjoying sunbathing by the water and a good temperature for other activities. For some people, it will be too hot in the direct sunlight and the stay may not be so pleasant. Don't forget to pack flip-flops, sunscreen, and a hand fan if necessary - it may come in handy.
What is the night temperature in September in Delaware?
The average night temperature in Delaware in September is 15 °C (59 °F). This temperature is pleasant for a wide range of evening, night, and morning activities from sports to sitting outside in restaurants or evening walks.
What is the sea temperature in September in Delaware?
In Delaware in September expect the sea to be warm at 22 °C (71 °F). The sea at this temperature is quite cold, but it is already possible to stay in it for a long time and it is pleasantly refreshing on hot, steamy days.
How many days of precipitation on average can I expect in September in Delaware?
In Delaware in September, we can expect 8 days to be rainy, that is, days when precipitation exceeds 2 mm (0.08 in). Converted to days of the week, this means that it will occur on an average of 2.0 days of the week, or in general - 28 % days.
What is the rainfall intensity in September in Delaware?
There is precipitation of 92 mm (3.62 in) in Delaware in September, which means 3 mm (0.12 in) rainfall per day on average.
Is there a wet season in September in Delaware?
No, there is no wet season in Delaware in September - you can expect 8 days of rain during the month.
How windy is it in September in Delaware?
In Delaware in September, there will be an average wind scale of 4.
How long is the day (from dawn till dusk) in Delaware in September?
The length of daylight in Delaware in September is 12 hours.
How many sunny hours can I expect in Delaware in September?
There is an average length of sunshine of 7 hours per day in Delaware in September.
Is it hot in September in Delaware?
In September in Delaware, you will enjoy nice warm weather, but it will also be pleasant and you probably won't feel hot.
How humid is Delaware in September?
In September in Delaware, expect humidity around 74 %.
Is Delaware rainier in September than in August?
No, in September in Delaware it does not rain more than in August.
Is the weather in Delaware warmer in September than in August?
No, September is not warmer in Delaware than August.
Is the sea in Delaware warmer in September than in October?
Yes, in Delaware in September the sea temperature is higher by 4 °C (39 °F) compared to October.