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
With the onset of September, Old Lyme experiences a modest temperature adjustment, with the average high-temperature gently receding from a warm 78.4°F (25.8°C) in August to a pleasant 72.1°F (22.3°C). Old Lyme usually reports an average low-temperature of 59.7°F (15.4°C) during the month of September.Humidity
The average relative humidity in September is 77%.Rainfall
The month with the least rainfall in Old Lyme is September, when the rain falls for 9.1 days and typically collects 0.35" (9mm) of precipitation.Snowfall
April through October are months without snowfall.Daylight
In Old Lyme, 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 7:21 pm. On the last day of the month, sunrise is at 6:45 am and sunset at 6:32 pm EDT.
Sunshine
In September, the average sunshine in Old Lyme is 8.9h.UV index
The average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV rays for ordinary individuals.Note: A maximum high UV index of 4 in September translates into the following recommendations:
Guard yourself - An obligation to protect skin and eyes from harm exists. Direct Sun exposure should be minimized especially during midday when radiation is most intense. To mitigate harm from sun exposure, pick sunglasses offering UVA and UVB defense.
Frequently asked questions
What are the temperatures in Old Lyme in September?
What is the average humidity in September in Old Lyme?
What is the driest month in Old Lyme?
How much does it rain in Old Lyme in September?
When it does not snow in Old Lyme?
How many hours of daylight does Old Lyme have in September?
When is the sunrise / sunset in September in Old Lyme?
How long on average sun shines in September in Old Lyme?
How high is the UV index in September in Old Lyme?
Average temperature in September
Old Lyme, CT
- Average high temperature in September: 72.1°F
The warmest month (with the highest average high temperature) is July (79.5°F).
The month with the lowest average high temperature is January (35.4°F).
- Average low temperature in September: 59.7°F
The month with the highest average low temperature is July (66.4°F).
The coldest month (with the lowest average low temperature) is January (25.7°F).
Average pressure in September
Old Lyme, 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
Old Lyme, CT
- Average wind speed in September: 8.1mph
The windiest month (with the highest average wind speed) is January (11.1mph).
The calmest month (with the lowest average wind speed) is July (7.2mph).
Average humidity in September
Old Lyme, CT
- Average humidity in September: 77%
The months with the highest relative humidity are June and July (79%).
The month with the lowest relative humidity is April (73%).
Average rainfall in September
Old Lyme, CT
- Average rainfall in September: 0.35"
The wettest month (with the highest rainfall) is December (0.94").
The driest month (with the least rainfall) is September (0.35").
Average rainfall days in September
Old Lyme, CT
- Average rainfall days in September: 9.1 days
The month with the highest number of rainy days is July (11.5 days).
The months with the least rainy days are February and November (6.6 days).
Average snowfall in September
Old Lyme, CT
- Average snowfall in September: 0"
The month with the highest snowfall is March (0.63").
The months with the least snowfall are April, May, June, July, August, September and October (0").
Average snowfall days in September
Old Lyme, CT
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (5.4 days).
The months with the least snowfall days are June, July, August, September and October (0 days).
Average daylight in September /
Average sunshine in September
Old Lyme, 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 months with the most sunshine are July and 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
Old Lyme, CT
- Average sunshine days in September: 19.3 days
The month with the most sunshine days is November (21.1 days).
The month with the least sunshine days is July (15.8 days).
Average UV index in September
Old Lyme, 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 Lyme, 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 28).
Average visibility in September
Old Lyme, 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 Lyme, Connecticut, USA
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