Contents
- Weather in September
- Frequently asked questions
- Average temperature in September
- Average pressure in September
- Average wind speed in September
- Average humidity in September
- Average rainfall in September
- Average rainfall days in September
- Average snowfall in September
- Average snowfall days in September
- Average daylight in September
- Average sunshine in September
- Average sunshine days in September
- Average UV index in September
- Average cloud cover in September
- Average visibility in September
Weather in September
Temperature
The shift from August to September includes a minor decrease in the average high-temperature, lightly dropping from a moderately hot 81°F (27.2°C) to a still warm 73.6°F (23.1°C). In September, the temperature drops to an average of 56.3°F (13.5°C) at night.Humidity
The average relative humidity in September is 77%.Rainfall
The month with the least rainfall is September, when the rain falls for 11.9 days and typically collects 1.89" (48mm) 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 the month, sunrise is at 6:17 am and sunset at 7:23 pm. On the last day of September, in Portland, Connecticut, sunrise is at 6:47 am and sunset at 6:33 pm EDT.
Sunshine
In September, the average sunshine is 8.5h.UV index
The average daily maximum UV index in September is 4. A UV Index reading of 3 to 5 represents a moderate threat to health from unprotected exposure to Sun's UV rays for average individuals.Note: In September, the maximum UV index of 4 suggests this advice:
Preventative actions are necessary - Recommendations to ward off sunburn are given. Stay safe from the Sun's strongest UV rays by limiting exposure during midday. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
What is the temperature in September?
What is the average humidity in September in Portland?
What is the driest month in Portland?
How much does it rain in September?
When it does not snow in Portland?
How many hours of daylight does Portland have in September?
When is the sunrise / sunset in September?
How long on average sun shines in September?
What is the UV index reading in September?
Average temperature in September
Portland, CT
- Average high temperature in September: 73.6°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 (34°F).
- Average low temperature in September: 56.3°F
The month with the highest average low temperature is July (64°F).
The coldest month (with the lowest average low temperature) is January (22.1°F).
Average pressure in September
Portland, CT
- Average pressure in September: 30.05"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
Portland, CT
- Average wind speed in September: 6mph
The windiest months (with the highest average wind speed) are January and March (8.3mph).
The calmest month (with the lowest average wind speed) is August (5.4mph).
Average humidity in September
Portland, 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 (71%).
Average rainfall in September
Portland, CT
- Average rainfall in September: 1.89"
The wettest month (with the highest rainfall) is December (3.66").
The driest month (with the least rainfall) is September (1.89").
Average rainfall days in September
Portland, CT
- Average rainfall days in September: 11.9 days
The month with the highest number of rainy days is July (17.2 days).
The month with the least rainy days is January (9.1 days).
Average snowfall in September
Portland, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (4.13").
The months with the least snowfall are June, July, August, September and October (0").
Average snowfall days in September
Portland, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average daylight in September /
Average sunshine in September
Portland, CT
- Average daylight in September: 12h and 3min
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 3min
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
Portland, CT
- Average sunshine days in September: 14.7 days
The month with the most sunshine days is November (17.2 days).
The month with the least sunshine days is June (11.3 days).
Average UV index in September
Portland, 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
Portland, CT
- Average cloud cover in September: 38
The month with the most cloud cover is February (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 33).
Average visibility in September
Portland, CT
- Average visibility in September: 6mi
The months with the highest visibility are January, March, April, August, September, October, November and December (6mi).
The months with the lowest visibility are February, May, June and July (5mi).
Portland, Connecticut, USA
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