September weather forecast
Portland, CT

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Weather in September

September, the first month of the autumn in Portland, is also a moderately hot month, with an average temperature ranging between min 56.3°F (13.5°C) and max 73.6°F (23.1°C).

Temperature

In September, the meteorological conditions change slightly, with the average high-temperature moving from 81°F (27.2°C) in August to a still moderately hot 73.6°F (23.1°C). During the nights in September, Portland experiences a consistent average temperature of 56.3°F (13.5°C).

Humidity

In Portland, 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, sunrise is at 6:47 am and sunset at 6:33 pm EDT.

Sunshine

In Portland, the average sunshine in September is 8.5h.

UV index

The average daily maximum UV index in September in Portland is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for average individuals.
Note: In September, the maximum UV index of 4 translates into these guidelines:
Undertake precautions - Guarding against sun damage is counselled. Sun exposure should be minimized, especially during midday, to avoid harmful UV radiation. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
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Frequently asked questions

What is the average September temperature in Portland?

The high-temperature in Portland, Connecticut, during September is 73.6°F (23.1°C) and the low-temperature is 56.3°F (13.5°C). The average heat index (a.k.a. 'real feel', 'felt air temperature'), which represents the influence of relative humidity on air temperature, in August is computed to be 86°F (30°C).

What is the average humidity in September in Portland?

The average relative humidity in September in Portland is 77%.

What is the driest month in Portland?

The month with the least rainfall in Portland, Connecticut, is September, when the rain falls for 11.9 days and typically collects 1.89" (48mm) of precipitation.

How many days does it rain in September in Portland?

In Portland, Connecticut, in September, it is raining for 11.9 days, with typically 1.89" (48mm) of accumulated precipitation.

When it does not snow in Portland?

June through October are months without snowfall in Portland, Connecticut.

How many hours of daylight does Portland have in September?

The average day length in September in Portland, Connecticut, is 12h and 28min.

What time are sunrise and sunset in September in Portland?

On the first day of September in Portland, 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.

How long on average sun shines in September in Portland?

In Portland, Connecticut, the average sunshine duration in September is 8.5h.

How high is the UV index in September in Portland?

In Portland, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a moderate health threat from unsafe exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average daylight
Average sunshine
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in September
Portland, CT

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).

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Average pressure in September
Portland, CT

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).

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Average wind speed in September
Portland, CT

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).

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Average humidity in September
Portland, CT

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%).

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Average rainfall in September
Portland, CT

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").

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Average rainfall days in September
Portland, CT

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).

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Average snowfall in September
Portland, CT

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").

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Average snowfall days in September
Portland, CT

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).

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Average daylight in September /
Average sunshine in September
Portland, CT

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).

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Average sunshine days in September
Portland, CT

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).

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Average UV index in September
Portland, CT

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).

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Average cloud cover in September
Portland, CT

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).

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Average visibility in September
Portland, CT

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).

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Portland, Connecticut, USA

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