Wilmington weather in September 2025

Expect 25°C daytime maximum temperatures in the shade with on average 7 hours of sunshine per day in Wilmington in September. Check more long-term weather averages for Wilmington in September before you book your next holiday to Delaware in 2025/2026.

  • 25°C maximum daytime temperature in September in Wilmington25
    25°C max day temperature
  • 7 hours of sunshine per day
  • 8 days with some rainfall in September in Wilmington8
    8 days with some rainfall
  • 14°C minimum night-time temperature in September in Wilmington14
    14°C min night temperature
  • 12 hours of daylight per day in September in Wilmington12
    12 hours of daylight per day
  • Low heat & humidity in September in WilmingtonL
    Low heat & humidity
  • 97 mm monthly rainfall in September in Wilmington97
    97 mm of monthly rainfall
  • UV (maximum) index 6 (High) in September in Wilmington6
    6 (High) UV index
  • 22°C sea temperature in September in Wilmington22
    22°C sea temperature

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The September weather guide for Delaware (Wilmington) shows long term weather averages processed from data supplied by CRU (University of East Anglia), the Met Office & the Netherlands Meteorological Institute. Find out more about our data sources.

Metric (°C / mm)  |  Imperial (°F / inches)

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How hot is it in Wilmington in September?

Daytime temperatures usually reach 25°C in Wilmington in September with low heat and humidity, falling to 14°C at night.

How sunny is it in Wilmington in September?

There are normally 7 hours of bright sunshine each day in Wilmington in September - that's 59% of daylight hours.

How warm is the sea around Wilmington in September?

The average sea temperature around Wilmington in September is 22°C.

Does it rain in Wilmington in September?

There are usually 8 days with some rain in Wilmington in September and the average monthly rainfall is 97mm.

What is the chance of a hurricane in Wilmington in September?

On average less than 1 day in September in Wilmington is likely to be affected by the passage of one or more tropical storms.

Wilmington September sunrise & sunset times

Browse the sunrise and sunset times for Wilmington in September 2025. Select a month to view Wilmington sunrise and sunset times for the next 12 months.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:31 18:33
Monday, 15th September 2025 05:44 18:10
Tuesday, 30th September 2025 05:58 17:46

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