September weather forecast
Deep River, CT

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Weather in September

The first month of the autumn, September, is also an agreeable month in Deep River, Connecticut, with an average temperature varying between 72.3°F (22.4°C) and 59.5°F (15.3°C).

Temperature

Deep River records a mild change in average high-temperature during September, easing from a moderately hot 78.6°F (25.9°C) in August to a pleasant 72.3°F (22.4°C). An average low-temperature of 59.5°F (15.3°C) is observed during the September nights.

Humidity

In Deep River, the average relative humidity in September is 77%.

Rainfall

September is the month with the least rainfall in Deep River. Rain falls for 13 days and accumulates 1.93" (49mm) of precipitation.

Snowfall

In Deep River, Connecticut, snow does not fall in June through October.

Daylight

In Deep River, Connecticut, the average length of the day in September is 12h and 28min.
On the first day of September, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm EDT.

Sunshine

In September, the average sunshine is 8.9h.

UV index

In Deep River, 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 the average person.
Note: A typical high UV index of 4 in September suggests the following recommendations:
Ensure safety - Imperative it is to shield skin and eyes from damage. Direct exposure to the Sun's intense radiation around midday should be avoided for health reasons. For a sun-safe wardrobe, go for clothes that are tightly woven and generously sized.
Updated: Aug 31, 2024
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate

Frequently asked questions

What is the usual temperature for Deep River in September?

In September, in Deep River, the average high-temperature is 72.3°F (22.4°C), and the average low-temperature is 59.5°F (15.3°C).

What is the average humidity in September?

In Deep River, the average relative humidity in September is 77%.

What is the driest month?

The month with the least rainfall is September, when the rain falls for 13 days and typically collects 1.93" (49mm) of precipitation.

How many days does it rain in September?

In Deep River, in September, during 13 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

When it does not snow?

In Deep River, snow does not fall in June through October.

How many hours of daylight does Deep River have in September?

In Deep River, the average day length in September is 12h and 28min.

When are sunrise and sunset in September in Deep River?

On the first day of September, sunrise is at 6:16 am and sunset at 7:22 pm. On the last day of the month, sunrise is at 6:46 am and sunset at 6:33 pm EDT.

How long on average sun shines in September?

The average sunshine duration in September is 8.9h.

What is the UV index reading in September?

The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium hazard to health from unprotected exposure to UV radiation.
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
Deep River, CT

Average temperature in September - Deep River, CT
  • Average high temperature in September: 72.3°F

The warmest month (with the highest average high temperature) is July (79.7°F).
The month with the lowest average high temperature is January (35.2°F).

  • Average low temperature in September: 59.5°F

The month with the highest average low temperature is July (66.6°F).
The coldest month (with the lowest average low temperature) is January (25.5°F).

Average pressure in September
Deep River, CT

Average pressure in September - Deep River, 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
Deep River, CT

Average wind speed in September - Deep River, CT
  • Average wind speed in September: 8.1mph

The windiest month (with the highest average wind speed) is January (10.9mph).
The calmest months (with the lowest average wind speed) are July and August (7.1mph).

Average humidity in September
Deep River, CT

Average humidity in September - Deep River, CT
  • Average humidity in September: 77%

The months with the highest relative humidity are May, June and July (78%).
The month with the lowest relative humidity is April (73%).

Average rainfall in September
Deep River, CT

Average rainfall in September - Deep River, CT
  • Average rainfall in September: 1.93"

The wettest month (with the highest rainfall) is December (3.66").
The driest month (with the least rainfall) is September (1.93").

Average rainfall days in September
Deep River, CT

Average rainfall days in September - Deep River, CT
  • Average rainfall days in September: 13 days

The month with the highest number of rainy days is July (17 days).
The month with the least rainy days is January (9 days).

Average snowfall in September
Deep River, CT

Average snowfall in September - Deep River, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.76").
The months with the least snowfall are June, July, August, September and October (0").

Average snowfall days in September
Deep River, CT

Average snowfall days in September - Deep River, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is February (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
Deep River, CT

Average daylight in September / Average sunshine in September - Deep River, 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 5min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The months with the least sunshine are February and December (Average sunshine: 4h and 48min).

Average sunshine days in September
Deep River, CT

Average sunshine days in September - Deep River, CT
  • Average sunshine days in September: 14.2 days

The month with the most sunshine days is November (17.1 days).
The month with the least sunshine days is July (11.7 days).

Average UV index in September
Deep River, CT

Average UV index in September - Deep River, 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
Deep River, CT

Average cloud cover in September - Deep River, CT
  • Average cloud cover in September: 33

The months with the most cloud cover are February and December (Cloud cover 48).
The month with the least cloud cover is August (Cloud cover 29).

Average visibility in September
Deep River, CT

Average visibility in September - Deep River, CT
  • Average visibility in September: 6mi

The months with the highest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).
The months with the lowest visibility are January, February, March, April, May, June, July, August, September, October, November and December (6mi).

Deep River, Connecticut, USA

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