Connecticut weather in September 2025

Expect 23°C daytime maximum temperatures in the shade with on average 7 hours of sunshine per day in Connecticut in September. Check more long-term weather averages for Connecticut in September before you book your next holiday to Connecticut in 2025/2026.

  • 23°C maximum daytime temperature in September in Connecticut (Hartford)23
    23°C max day temperature
  • 7 hours of sunshine per day
  • 9 days with some rainfall in September in Connecticut (Hartford)9
    9 days with some rainfall
  • 11°C minimum night-time temperature in September in Connecticut (Hartford)11
    11°C min night temperature
  • 12 hours of daylight per day in September in Connecticut (Hartford)12
    12 hours of daylight per day
  • No heat & humidity in September in Connecticut (Hartford)0
    No heat & humidity
  • 95 mm monthly rainfall in September in Connecticut (Hartford)95
    95 mm of monthly rainfall
  • UV (maximum) index 6 (High) in September in Connecticut (Hartford)6
    6 (High) UV index

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The September weather guide for Connecticut (Hartford) 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.

Top Connecticut destinations

Below are average maximum temperatures at popular countries, regions and places in Connecticut in September. Select a holiday destination to see more weather parameters.

All Connecticut destinations

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

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How hot is it in Connecticut in September?

Daytime temperatures usually reach 23°C in Hartford, Connecticut in September, falling to 11°C at night.

How sunny is it in Connecticut in September?

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

Does it rain in Connecticut in September?

There are usually 9 days with some rain in Hartford, Connecticut in September and the average monthly rainfall is 95mm.

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

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

Connecticut September sunrise & sunset times

Browse the sunrise and sunset times for Connecticut in September 2025. Select a month to view Connecticut sunrise and sunset times for the next 12 months. The Connecticut sunrise and sunset times shown below are for Hartford.

JanFebMarAprMayJunJulAugSepOctNovDec

Date Sunrise times Sunset times
Monday, 1st September 2025 05:17 18:24
Monday, 15th September 2025 05:31 18:00
Tuesday, 30th September 2025 05:47 17:34

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