September weather forecastNewtown, CT
September
Weather in September
With the arrival of September, Newtown, Connecticut starts to reflect the stunning changes of autumn. Despite this, the temperature still hovers in the mild range with a peak of 73°F (22.8°C). As the city shifts from summer to fall, daylight hours reduce further, casting longer shadows that add to Newtown's autumn charm. The cityscape begins to transform, adopting earthy hues from the changing foliage. September ushers in cooler winds, shorter days, and scenic beauty indicative of the imminent fall season.Temperature
The average high-temperature shows a slight dip in September, from August's moderately hot 80.2°F (26.8°C) to a pleasant 73°F (22.8°C). An average minimum temperature of 57°F (13.9°C) marks the month of September.Humidity
The average relative humidity in September is 77%.Rainfall
January and September are months with the least rain in Newtown when the rain falls for 13.4 days and typically aggregates up to 2.4" (61mm) of rain.Snowfall
June through September are months without snowfall in Newtown.Daylight
In Newtown, the average length of the day in September is 12h and 28min.On the first day of the month, sunrise is at 6:20 am and sunset at 7:25 pm. On the last day of September, in Newtown, Connecticut, sunrise is at 6:49 am and sunset at 6:36 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV radiation for ordinary individuals.Note: The UV index of 4 during September leads to these advisories:
Make use of precautions - It is urged to ward off sun damage. The mid-day Sun emits the most powerful UV radiation, so seek shade and minimize exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
Newtown, CT
- Average high temperature in September: 73°F
The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (33.4°F).
- Average low temperature in September: 57°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in September
Newtown, 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
Newtown, CT
- Average wind speed in September: 6.1mph
The windiest month (with the highest average wind speed) is January (8.5mph).
The calmest month (with the lowest average wind speed) is August (5.3mph).
Average humidity in September
Newtown, 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 (72%).
Average rainfall in September
Newtown, CT
- Average rainfall in September: 2.4"
The wettest month (with the highest rainfall) is December (4.02").
The driest months (with the least rainfall) are January and September (2.4").
Average rainfall days in September
Newtown, CT
- Average rainfall days in September: 13.4 days
The month with the highest number of rainy days is July (18.6 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in September
Newtown, CT
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.37").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Newtown, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (9.5 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Newtown, 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 42min
The months with the most sunshine are July and August (Average sunshine: 10h and 18min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Newtown, CT
- Average sunshine days in September: 13.9 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (10.1 days).
Average UV index in September
Newtown, 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
Newtown, CT
- Average cloud cover in September: 36
The months with the most cloud cover are February, March and December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Newtown, CT
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are February and May (5mi).
