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 sea temperature 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
In the transition to September, Old Greenwich observes a minor drop in the average high-temperature, shifting from a warm 80.4°F (26.9°C) in August to an agreeable 73.2°F (22.9°C). Old Greenwich records a mean low-temperature of 61.7°F (16.5°C) in September.Humidity
In September, the average relative humidity is 73%.Rainfall
In Old Greenwich, in September, during 13.3 rainfall days, 2.68" (68mm) of precipitation is typically accumulated. Throughout the year, in Old Greenwich, there are 166.6 rainfall days, and 38.07" (967mm) of precipitation is accumulated.Snowfall
May through October are months without snowfall in Old Greenwich.Ocean temperature
In Old Greenwich, in September, the average water temperature is 68.9°F (20.5°C).Note: Swimming in 68.9°F (20.5°C) is not pleasurable for most people. Breathing control grows increasingly challenging as the water temperature falls under 69.8°F (21°C).
Daylight
The average length of the day in September in Old Greenwich is 12h and 28min.On the first day of September in Old Greenwich, Connecticut, sunrise is at 6:21 am and sunset at 7:26 pm. On the last day of the month, sunrise is at 6:50 am and sunset at 6:37 pm EDT.
Sunshine
In Old Greenwich, the average sunshine in September is 8.8h.UV index
In September, the average daily maximum UV index is 4. A UV Index of 3 to 5 symbolizes a moderate threat to health from exposure to the Sun's UV rays for the average person.Note: The maximum daily UV index of 4 during September translates into the following directions:
Heed the precautions - It is counselled to guard against solar damage. The Sun's radiation is especially intense around midday; try to stay in shade during this period. Select sunglasses that boast both UVA and UVB protection to limit the adverse effects of the sun on the eyes.
Frequently asked questions
What is the average September temperature in Old Greenwich?
What is the average humidity in September in Old Greenwich?
How many days does it rain in September in Old Greenwich?
When it does not snow in Old Greenwich?
What is the ocean temperature in September in Old Greenwich?
How many hours of daylight does Old Greenwich have in September?
When is the sunrise / sunset in September in Old Greenwich?
How long on average sun shines in September in Old Greenwich?
How high is the UV index in September in Old Greenwich?
Average temperature in September
Old Greenwich, CT
- Average high temperature in September: 73.2°F
The warmest month (with the highest average high temperature) is July (81.9°F).
The month with the lowest average high temperature is January (36°F).
- Average low temperature in September: 61.7°F
The month with the highest average low temperature is July (69.3°F).
The coldest month (with the lowest average low temperature) is January (26.2°F).
Average pressure in September
Old Greenwich, 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
Old Greenwich, CT
- Average wind speed in September: 7.6mph
The windiest month (with the highest average wind speed) is January (10.1mph).
The calmest month (with the lowest average wind speed) is July (6.6mph).
Average humidity in September
Old Greenwich, CT
- Average humidity in September: 73%
The months with the highest relative humidity are February, May, June and December (75%).
The month with the lowest relative humidity is August (71%).
Average rainfall in September
Old Greenwich, CT
- Average rainfall in September: 2.68"
The wettest month (with the highest rainfall) is July (4.13").
The driest month (with the least rainfall) is January (2.44").
Average rainfall days in September
Old Greenwich, CT
- Average rainfall days in September: 13.3 days
The month with the highest number of rainy days is July (17.8 days).
The month with the least rainy days is January (8.6 days).
Average snowfall in September
Old Greenwich, CT
- Average snowfall in September: 0"
The month with the highest snowfall is February (2.6").
The months with the least snowfall are May, June, July, August, September and October (0").
Average snowfall days in September
Old Greenwich, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is February (7.3 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
Old Greenwich, CT
- Average sea temperature in September: 68.9°F
The best month for swimming (with the highest average sea temperature) is August (73.1°F).
The coldest month (with the lowest average sea temperature) is February (39.5°F).
Average daylight in September /
Average sunshine in September
Old Greenwich, 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 18min).
- Average sunshine in September: 8h and 5min
The month with the most sunshine is July (Average sunshine: 10h and 30min).
The months with the least sunshine are February and December (Average sunshine: 4h and 42min).
Average sunshine days in September
Old Greenwich, CT
- Average sunshine days in September: 14.8 days
The month with the most sunshine days is November (17.9 days).
The month with the least sunshine days is June (11.1 days).
Average UV index in September
Old Greenwich, 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
Old Greenwich, CT
- Average cloud cover in September: 35
The month with the most cloud cover is December (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).
Average visibility in September
Old Greenwich, 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).
Old Greenwich, Connecticut, USA
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