September weather forecastHartford, CT
September
Weather in September
With September arrives the advent of autumn in Hartford, Connecticut. The environment begins to respond, embracing gradual climatic shifts. As the weather starts cooling down, the city experiences a high of 73.4°F (23°C). The cityscape gets a new paint job, trading the vibrant green scenery for a deep, rustic orange. September's climate thus embodies a welcome change, bidding farewell to the intense summer and greeting the refreshing autumn.Temperature
September's onset in Hartford corresponds with a subtle shift in the average high-temperature, slightly moving from 81°F (27.2°C) in August to a still warm 73.4°F (23°C). Hartford reports an average low-temperature of 55.2°F (12.9°C) during the nights of September.Humidity
The average relative humidity in September in Hartford is 77%.Rainfall
September is the month with the least rainfall in Hartford. Rain falls for 8.2 days and accumulates 0.43" (11mm) of precipitation.Snowfall
June through October are months without snowfall.Daylight
The average length of the day in September is 12h and 28min.On the first day of September in Hartford, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of the month, sunrise is at 6:47 am and sunset at 6:33 pm EDT.
Sunshine
In September, the average sunshine in Hartford, Connecticut, is 8.7h.UV index
In September, the average daily maximum UV index in Hartford is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from exposure to the Sun's UV radiation for the average person.Note: The UV index of 4 during September translates into the following guidance:
Exercise prudence. Persons with fair skin could be burned in under 30 minutes. Minimize direct exposure to the Sun during midday when its radiation is at its peak. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Hartford, CT
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (82.9°F).
The month with the lowest average high temperature is January (33.1°F).
- Average low temperature in September: 55.2°F
The month with the highest average low temperature is July (63.7°F).
The coldest month (with the lowest average low temperature) is January (21.4°F).
Average pressure in September
Hartford, CT
- Average pressure in September: 30.06"Hg
The month with the highest atmospheric pressure is November (30.09"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Hartford, CT
- Average wind speed in September: 5.8mph
The windiest months (with the highest average wind speed) are January and March (8.1mph).
The calmest months (with the lowest average wind speed) are July and August (5.3mph).
Average humidity in September
Hartford, CT
- Average humidity in September: 77%
The month with the highest relative humidity is February (79%).
The month with the lowest relative humidity is April (70%).
Average rainfall in September
Hartford, CT
- Average rainfall in September: 0.43"
The wettest months (with the highest rainfall) are June and July (1.06").
The driest month (with the least rainfall) is September (0.43").
Average rainfall days in September
Hartford, CT
- Average rainfall days in September: 8.2 days
The month with the highest number of rainy days is July (11.8 days).
The month with the least rainy days is February (6.8 days).
Average snowfall in September
Hartford, CT
- Average snowfall in September: 0"
The month with the highest snowfall is February (1.14").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Hartford, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.7 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Hartford, CT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 42min
The months with the most sunshine are July and August (Average sunshine: 10h and 24min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Hartford, CT
- Average sunshine days in September: 20.3 days
The months with the most sunshine days are January and November (20.4 days).
The month with the least sunshine days is June (16.3 days).
Average UV index in September
Hartford, CT
- Average UV index in September: 4
The months with the highest UV index are June, July and August (UV index 6).
The months with the lowest UV index are January, February, March, November and December (UV index 2).
Average cloud cover in September
Hartford, CT
- Average cloud cover in September: 37
The month with the most cloud cover is February (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Hartford, CT
- Average visibility in September: 5mi
The months with the highest visibility are January, March, April, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July, August and September (5mi).
