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The temperatures in Connecticut in September are comfortable with low of 14°C and and high up to 24°C.
You can expect about 3 to 8 days of rain in Connecticut during the month of September. It’s a good idea to bring along your umbrella so that you don’t get caught in poor weather.
Our weather forecast can give you a great sense of what weather to expect in Connecticut in September 2025.
If you’re planning to visit Connecticut in the near future, we highly recommend that you review the 14 day weather forecast for Connecticut before you arrive.
| Month | Temperatures | Rainy Days | Dry Days | Snowy Days | Rainfall | Weather | More details |
|---|---|---|---|---|---|---|---|
| January | 1° / -5° | 5 | 18 | 8 | 60 mm | Awful | Connecticut in January |
| February | 2° / -5° | 5 | 13 | 10 | 66 mm | Awful | Connecticut in February |
| March | 7° / -1° | 5 | 19 | 7 | 71 mm | Bad | Connecticut in March |
| April | 14° / 5° | 5 | 24 | 1 | 68 mm | Good | Connecticut in April |
| May | 20° / 10° | 5 | 26 | 0 | 67 mm | Good | Connecticut in May |
| June | 25° / 14° | 5 | 25 | 0 | 75 mm | Perfect | Connecticut in June |
| July | 28° / 18° | 5 | 26 | 0 | 91 mm | Perfect | Connecticut in July |
| August | 28° / 17° | 4 | 27 | 0 | 89 mm | Perfect | Connecticut in August |
| September | 24° / 14° | 3 | 27 | 0 | 56 mm | Perfect | Connecticut in September |
| October | 17° / 9° | 5 | 26 | 0 | 81 mm | Good | Connecticut in October |
| November | 10° / 3° | 4 | 24 | 1 | 58 mm | Ok | Connecticut in November |
| December | 4° / -1° | 6 | 19 | 6 | 72 mm | Awful | Connecticut in December |