September weather forecastSouth Yarmouth, MA
September
Weather in September
September, the first month of the autumn in South Yarmouth, is still a refreshing month, with an average temperature fluctuating between 67.1°F (19.5°C) and 63°F (17.2°C).Temperature
The advent of September signifies a minor shift to an average high-temperature of a comfortable 67.1°F (19.5°C), aligning closely with August. A minor drop in temperature is observed from daytime highs during the nights of September, averaging a still enjoyable 63°F (17.2°C).Humidity
In South Yarmouth, the average relative humidity in September is 79%.Rainfall
In September, the rain falls for 9.5 days. Throughout September, 1.18" (30mm) of precipitation is accumulated. In South Yarmouth, during the entire year, the rain falls for 129 days and collects up to 14.21" (361mm) of precipitation.Snowfall
In South Yarmouth, snow does not fall in May through November.Ocean temperature
In South Yarmouth, the average seawater temperature in September is 64.2°F (17.9°C).Note: Most people find swimming in 64.2°F (17.9°C) unenjoyable. As the water temperature falls from 69.8°F (21°C) to 59°F (15°C), controlling one's breathing becomes harder.
Daylight
In September, the average length of the day is 12h and 28min.On the first day of the month, sunrise is at 6:07 am and sunset at 7:13 pm. On the last day of September, sunrise is at 6:37 am and sunset at 6:23 pm EDT.
Sunshine
In September, the average sunshine is 8.7h.UV index
The average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium health hazard from exposure to the Sun's UV radiation for average individuals.Note: In September, the maximum UV index of 4 suggests these recommendations:
Adopt protective measures - Requirement to safeguard skin and eyes from harm exists. Midday Sun has the strongest UV rays, making it crucial to limit exposure and find shade. Consider a wide-brim hat essential for effective sun defense covering your face, neck, and eyes.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
Average temperature in September
South Yarmouth, MA
- Average high temperature in September: 67.1°F
The warmest month (with the highest average high temperature) is August (72.1°F).
The month with the lowest average high temperature is January (38.5°F).
- Average low temperature in September: 63°F
The month with the highest average low temperature is August (68.5°F).
The coldest month (with the lowest average low temperature) is January (30.6°F).
Average pressure in September
South Yarmouth, MA
- Average pressure in September: 30.05"Hg
The month with the highest atmospheric pressure is November (30.06"Hg).
The month with the lowest atmospheric pressure is June (29.93"Hg).
Average wind speed in September
South Yarmouth, MA
- Average wind speed in September: 12.8mph
The windiest month (with the highest average wind speed) is January (16.8mph).
The calmest months (with the lowest average wind speed) are July and August (10.9mph).
Average humidity in September
South Yarmouth, MA
- Average humidity in September: 79%
The months with the highest relative humidity are June and July (84%).
The month with the lowest relative humidity is November (74%).
Average rainfall in September
South Yarmouth, MA
- Average rainfall in September: 1.18"
The wettest month (with the highest rainfall) is October (1.93").
The driest month (with the least rainfall) is August (0.94").
Average rainfall days in September
South Yarmouth, MA
- Average rainfall days in September: 9.5 days
The month with the highest number of rainy days is May (12.5 days).
The month with the least rainy days is February (8.3 days).
Average snowfall in September
South Yarmouth, MA
- Average snowfall in September: 0"
The month with the highest snowfall is January (0.87").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in September
South Yarmouth, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.4 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).
Average sea temperature in September
South Yarmouth, MA
- Average sea temperature in September: 64.3°F
The best month for swimming (with the highest average sea temperature) is August (67.5°F).
The coldest month (with the lowest average sea temperature) is March (39°F).
Average daylight in September /
Average sunshine in September
South Yarmouth, MA
- Average daylight in September: 12h and 30min
The month with the longest days is June (Average daylight: 15h and 12min).
The month with the shortest days is December (Average daylight: 9h and 12min).
- Average sunshine in September: 8h and 42min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The months with the least sunshine are February and December (Average sunshine: 4h and 36min).
Average sunshine days in September
South Yarmouth, MA
- Average sunshine days in September: 18.6 days
The month with the most sunshine days is September (18.6 days).
The month with the least sunshine days is February (14.3 days).
Average UV index in September
South Yarmouth, MA
- Average UV index in September: 4
The months with the highest UV index are 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
South Yarmouth, MA
- Average cloud cover in September: 31
The month with the most cloud cover is December (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
South Yarmouth, MA
- 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).
