September weather forecast
Connecticut, USA

September in Connecticut marks the beginning of the fall season, with noticeable changes in temperature and a reduction in humidity. The hot summer weather begins to give way to milder conditions, though the transition can vary throughout the state.

Average high temperatures decrease to the range of 65°F (18.3°C) to 70°F (21.1°C), especially in northern and inland areas. Coastal regions might experience slightly warmer conditions due to the proximity to water bodies.

Rainfall remains consistent with the annual range of 44" (1118mm) to 48" (1219mm), but thunderstorms become less frequent. Precipitation may still occur but often in the form of gentler rain showers rather than intense storms.

Humidity continues to decrease, contributing to the more comfortable and crisp weather associated with the beginning of fall. The oppressive humidity of the summer months is largely gone, replaced by fresher and more invigorating air.

The decrease in temperature and humidity also brings the onset of colorful foliage. The transformation begins in the north and gradually moves to the south, with leaves turning vibrant shades of red, orange, and yellow.

September's weather in Connecticut reflects a clear transition from summer to fall, characterized by milder temperatures, reduced humidity, and the beginning of the state's famous foliage season. The changes are often gradual, with the warmth of summer lingering in the early part of the month before giving way to the unmistakable signs of fall. The shift from the heat and humidity of August to the cooler and more comfortable conditions of September is often welcome, heralding the arrival of one of New England's most picturesque and pleasant seasons.

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• Hartford - September »
  In Hartford during September, the rain falls for 8.2 days and regularly aggregates up to 0.43" (11mm) of precipitation. On the first day of September in Hartford, sunrise is at 6:17 am and sunset at 7:23 pm.
• New Haven - September »
  The month with the least rainfall in New Haven is September, when the rain falls for 13.4 days and typically collects 2.24" (57mm) of precipitation. In New Haven, entering September brings a subtle temperature decrement, reducing from August's warm 79.7°F (26.5°C) to an agreeable 72.5°F (22.5°C).
• Stamford - September »
  In Stamford in September, during 13.5 rainfall days, 2.76" (70mm) of precipitation is typically accumulated. In Stamford, in September, during 13.5 rainfall days, 2.76" (70mm) of precipitation is typically accumulated.
• Bridgeport - September »
  On the first day of September in Bridgeport, Connecticut, sunrise is at 6:20 am and sunset at 7:25 pm. In Bridgeport, Connecticut, in September, the average water temperature is 68.7°F (20.4°C).
• Waterbury - September »
  The month with the least rainfall in Waterbury is September, when the rain falls for 13 days and typically collects 2.13" (54mm) of precipitation. The month with the least rainfall in Waterbury is September, when the rain falls for 13 days and typically collects 2.13" (54mm) of precipitation.
• Norwalk - September »
  On the first day of September in Norwalk sunrise is at 6:20 am and sunset at 7:25 pm. In September, the average ocean temperature in Norwalk is 68.7°F (20.4°C).
• Danbury - September »
  In Danbury during September, the rain falls for 9.7 days and regularly aggregates up to 0.67" (17mm) of precipitation. On the last day of September, in Danbury, sunrise is at 6:50 am and sunset at 6:36 pm EDT.
• New Britain - September »
  The month with the least rainfall in New Britain is September, when the rain falls for 12.5 days and typically collects 1.97" (50mm) of precipitation. In New Britain, during September, the rain falls for 12.5 days and regularly aggregates up to 1.97" (50mm) of precipitation.
• Bristol - September »
  On the first day of September in Bristol sunrise is at 6:18 am and sunset at 7:24 pm. In Bristol, in September, during 13.6 rainfall days, 2.24" (57mm) of precipitation is typically accumulated.
• Meriden - September »
  In September, Autumn graces Meriden with milder temperatures and shorter daylight hours. How many hours of sunshine does Meriden have in September?
• Milford - September »
  The month with the least rainfall in Milford is September, when the rain falls for 13.5 days and typically collects 2.4" (61mm) of precipitation. The month with the least rainfall in Milford is September, when the rain falls for 13.5 days and typically collects 2.4" (61mm) of precipitation.
• West Haven - September »
  The month with the least rainfall in West Haven is September, when the rain falls for 13.4 days and typically collects 2.24" (57mm) of precipitation. West Haven's weather in September involves a mild decrease in the average high-temperature, moving down slightly from August's moderately hot 79.7°F (26.5°C) to a pleasant 72.5°F (22.5°C).