September weather forecast
Mystic, CT

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Weather in September

September bids goodbye to summer with a notable decrease in temperature scale. The average high drops to 71.4°F (21.9°C), a perfect transition from the hot summer towards the cooler autumn. As autumn colors start to show, the city of Mystic transforms into an artist's palette with hues of gold, orange, and red. The month's climatic conditions with its comfortable warmth during the day and cooler evenings make it a favored time for visitors. Enjoy walking tours through the splendid historic sites or boat tours appreciating the onset of the beautiful fall foliage.

Temperature

As August makes way for September, Mystic's average high-temperature eases from a warm 77.7°F (25.4°C) to a pleasant 71.4°F (21.9°C). In Mystic, September nights witness a steady temperature drop to a refreshing 59.9°F (15.5°C).

Humidity

In September, the average relative humidity in Mystic, Connecticut, is 78%.

Rainfall

September is the month with the least rainfall. Rain falls for 12.8 days and accumulates 1.73" (44mm) of precipitation.

Snowfall

In Mystic, snow does not fall in May through September.

Ocean temperature

In Mystic, in September, the average water temperature is 67.6°F (19.8°C).
Note: The enjoyment of swimming decreases for most when the surface water temperature is 67.6°F (19.8°C). Breathing control becomes increasingly challenging as temperatures descend below 69.8°F (21°C).

Daylight

In September, the average length of the day is 12h and 28min.
On the first day of the month, sunrise is at 6:14 am and sunset at 7:20 pm. On the last day of September, sunrise is at 6:44 am and sunset at 6:30 pm EDT.

Sunshine

The average sunshine in September in Mystic is 8.9h.

UV index

In Mystic, Connecticut, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.
Note: The daily maximum UV index of 4 in September interprets into the following advice:
Put precautions into practice - Protective measures against sun-induced damage are advised. To prevent harmful UV exposure, minimize direct contact with the Sun around midday. Employ a hat with a wide brim for robust protection, cutting UV exposure by half.
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Frequently asked questions

What are the temperatures in Mystic in September?

The average high-temperature, in September, in Mystic, is 71.4°F (21.9°C), while the average low-temperature is 59.9°F (15.5°C).

What is the average humidity in September in Mystic?

In September, the average relative humidity in Mystic, Connecticut, is 78%.

What is the driest month in Mystic?

September is the month with the least rainfall in Mystic. Rain falls for 12.8 days and accumulates 1.73" (44mm) of precipitation.

How many days does it rain in September in Mystic?

In September, in Mystic, Connecticut, the rain falls for 12.8 days. Throughout September, 1.73" (44mm) of precipitation is accumulated.

When it does not snow in Mystic?

May through September are months without snowfall in Mystic, Connecticut.

Does it snow in Mystic in September?

In Mystic, Connecticut, in September, it doesn't snow. In October, it regularly snows.

How cold is the water in September in Mystic?

In Mystic, the average seawater temperature in September is 67.6°F (19.8°C). Swimming in 67.6°F (19.8°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

How many hours of daylight does Mystic have in September?

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

What time are sunrise and sunset in September in Mystic?

In September, on the first day of the month, sunrise is at 6:14 am and sunset at 7:20 pm. On the last day of the month, sunrise is at 6:44 am and sunset at 6:30 pm EDT.

How long on average sun shines in September in Mystic?

In September, the average sunshine duration in Mystic, Connecticut, is 8.9h.

What is the UV index intensity in September in Mystic?

In Mystic, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health risk from 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
Mystic, CT

Average temperature in September - Mystic, CT
  • Average high temperature in September: 71.4°F

The warmest month (with the highest average high temperature) is July (77.9°F).
The month with the lowest average high temperature is January (36.5°F).

  • Average low temperature in September: 59.9°F

The month with the highest average low temperature is July (66.9°F).
The coldest month (with the lowest average low temperature) is January (26.6°F).

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Average pressure in September
Mystic, CT

Average pressure in September - Mystic, 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).

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Average wind speed in September
Mystic, CT

Average wind speed in September - Mystic, CT
  • Average wind speed in September: 9.2mph

The windiest month (with the highest average wind speed) is January (12.4mph).
The calmest month (with the lowest average wind speed) is August (8.1mph).

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Average humidity in September
Mystic, CT

Average humidity in September - Mystic, CT
  • Average humidity in September: 78%

The month with the highest relative humidity is June (81%).
The months with the lowest relative humidity are January, March, April and November (74%).

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Average rainfall in September
Mystic, CT

Average rainfall in September - Mystic, CT
  • Average rainfall in September: 1.73"

The wettest month (with the highest rainfall) is December (3.86").
The driest month (with the least rainfall) is September (1.73").

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Average rainfall days in September
Mystic, CT

Average rainfall days in September - Mystic, CT
  • Average rainfall days in September: 12.8 days

The month with the highest number of rainy days is July (17.1 days).
The month with the least rainy days is February (10.1 days).

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Average snowfall in September
Mystic, CT

Average snowfall in September - Mystic, CT
  • Average snowfall in September: 0"

The month with the highest snowfall is March (2.44").
The months with the least snowfall are May, June, July, August and September (0").

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Average snowfall days in September
Mystic, CT

Average snowfall days in September - Mystic, CT
  • Average snowfall days in September: 0 days

The month with the highest number of snowfall days is January (6.8 days).
The months with the least snowfall days are May, June, July, August and September (0 days).

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Average sea temperature in September
Mystic, CT

Average sea temperature in September - Mystic, CT
  • Average sea temperature in September: 67.6°F

The best month for swimming (with the highest average sea temperature) is August (70.3°F).
The coldest month (with the lowest average sea temperature) is February (37.9°F).

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

Average daylight in September / Average sunshine in September - Mystic, 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 54min).

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Average sunshine days in September
Mystic, CT

Average sunshine days in September - Mystic, CT
  • Average sunshine days in September: 15.2 days

The month with the most sunshine days is November (16.5 days).
The months with the least sunshine days are June and July (11.7 days).

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Average UV index in September
Mystic, CT

Average UV index in September - Mystic, 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 and December (UV index 2).

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Average cloud cover in September
Mystic, CT

Average cloud cover in September - Mystic, CT
  • Average cloud cover in September: 32

The months with the most cloud cover are February, March and December (Cloud cover 47).
The month with the least cloud cover is August (Cloud cover 28).

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Average visibility in September
Mystic, CT

Average visibility in September - Mystic, 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).

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Mystic, Connecticut, USA

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