September weather forecastHaddam, CT
September
Weather in September
September, the first month of the autumn in Haddam, is also a moderately hot month, with temperature in the range of an average high of 73.4°F (23°C) and an average low of 56.7°F (13.7°C).Temperature
In Haddam, the average high-temperature in September slightly decreases from 80.4°F (26.9°C) in August to a still warm 73.4°F (23°C). In September, Haddam encounters an average low-temperature of 56.7°F (13.7°C) during the night.Humidity
The average relative humidity in September is 77%.Rainfall
The month with the least rainfall is September, when the rain falls for 8.5 days and typically collects 0.39" (10mm) of precipitation.Snowfall
In Haddam, snow does not fall in June through October.Daylight
The average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of September, sunrise is at 6:46 am and sunset at 6:33 pm EDT.
Sunshine
The average sunshine in September is 8.3h.UV index
In Haddam, Connecticut, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health risk from exposure to the Sun's UV radiation for the average person.Note: In September, an average UV index of 4 transforms into the following instructions:
Undertake protective steps - Obligation to safeguard skin and eyes from harm is in place. The best time to avoid the Sun's harmful UV radiation is during midday when it's most potent. Shield yourself from the harmful effects of UV radiation with sun-protective attire, a hat, and quality sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Haddam, CT
- Average high temperature in September: 73.4°F
The warmest month (with the highest average high temperature) is July (82.6°F).
The month with the lowest average high temperature is January (34.7°F).
- Average low temperature in September: 56.7°F
The month with the highest average low temperature is July (63.9°F).
The coldest month (with the lowest average low temperature) is January (22.8°F).
Average pressure in September
Haddam, CT
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.08"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
Haddam, CT
- Average wind speed in September: 6.3mph
The windiest months (with the highest average wind speed) are January and March (8.6mph).
The calmest months (with the lowest average wind speed) are July and August (5.7mph).
Average humidity in September
Haddam, CT
- Average humidity in September: 77%
The month with the highest relative humidity is February (78%).
The month with the lowest relative humidity is April (72%).
Average rainfall in September
Haddam, CT
- Average rainfall in September: 0.39"
The wettest month (with the highest rainfall) is July (1.18").
The driest month (with the least rainfall) is September (0.39").
Average rainfall days in September
Haddam, CT
- Average rainfall days in September: 8.5 days
The month with the highest number of rainy days is July (12.7 days).
The month with the least rainy days is January (5.9 days).
Average snowfall in September
Haddam, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (1.14").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Haddam, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (5.2 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Haddam, CT
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 18min
The months with the most sunshine are July and August (Average sunshine: 10h and 6min).
The month with the least sunshine is February (Average sunshine: 4h and 30min).
Average sunshine days in September
Haddam, CT
- Average sunshine days in September: 19.1 days
The month with the most sunshine days is November (20.9 days).
The month with the least sunshine days is July (16.3 days).
Average UV index in September
Haddam, 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
Haddam, CT
- Average cloud cover in September: 39
The months with the most cloud cover are February and March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 35).
Average visibility in September
Haddam, CT
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, September, October, November and December (6mi).
The months with the lowest visibility are February, May, June, July and August (5mi).
