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
The shift to September signals an average high-temperature of an enjoyable 67.5°F (19.7°C), subtly varied from August's 72.5°F (22.5°C). In Dennis, September nights experience a modest descent in temperature from daily peaks, cooling down to an average of 62.8°F (17.1°C).Humidity
The average relative humidity in September in Dennis is 79%.Rainfall
In Dennis, during September, the rain falls for 9.4 days and regularly aggregates up to 1.1" (28mm) of precipitation. In Dennis, during the entire year, the rain falls for 129.6 days and collects up to 13.94" (354mm) of precipitation.Snowfall
May through November are months without snowfall in Dennis.Daylight
In September, the average length of the day is 12h and 28min.On the first day of September in Dennis, sunrise is at 6:07 am and sunset at 7:13 pm. On the last day of the month, sunrise is at 6:37 am and sunset at 6:23 pm EDT.
Sunshine
In September, the average sunshine is 8.8h.UV index
In Dennis, the average daily maximum UV index in September is 4. A UV Index estimate of 3 to 5 represents a medium health hazard from exposure to the Sun's UV rays for the ordinary person.Note: The daily high UV index of 4 in September translates into this advice:
Exercise prevention - Warding off sunburn is urged. Avoiding direct sun during mid-day hours can prevent harmful UV radiation exposure. Opt for tightly woven and loose clothing to enhance protection from the Sun.
Frequently asked questions
What is the usual temperature for Dennis in September?
What is the average humidity in September in Dennis?
How many days does it rain in September in Dennis?
When it does not snow in Dennis?
What is the average length of the day in September in Dennis?
When is the sunrise / sunset in September in Dennis?
How long on average sun shines in September in Dennis?
What is the UV index reading in September in Dennis?
Average temperature in September
Dennis, MA
- Average high temperature in September: 67.5°F
The warmest month (with the highest average high temperature) is August (72.5°F).
The month with the lowest average high temperature is January (38.3°F).
- Average low temperature in September: 62.8°F
The month with the highest average low temperature is August (68.2°F).
The coldest month (with the lowest average low temperature) is January (30.4°F).
Average pressure in September
Dennis, 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
Dennis, MA
- Average wind speed in September: 12.4mph
The windiest month (with the highest average wind speed) is January (16.4mph).
The calmest month (with the lowest average wind speed) is August (10.4mph).
Average humidity in September
Dennis, MA
- Average humidity in September: 79%
The months with the highest relative humidity are May, June and July (83%).
The month with the lowest relative humidity is November (74%).
Average rainfall in September
Dennis, MA
- Average rainfall in September: 1.1"
The wettest month (with the highest rainfall) is October (1.89").
The driest month (with the least rainfall) is August (0.94").
Average rainfall days in September
Dennis, MA
- Average rainfall days in September: 9.4 days
The month with the highest number of rainy days is May (13.2 days).
The month with the least rainy days is February (8.1 days).
Average snowfall in September
Dennis, MA
- Average snowfall in September: 0"
The months with the highest snowfall are January and February (0.63").
The months with the least snowfall are May, June, July, August, September, October and November (0").
Average snowfall days in September
Dennis, MA
- Average snowfall days in September: 0 days
The month with the highest number of snowfall days is January (6.6 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
Dennis, MA
- Average daylight in September: 12h and 3min
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 5min
The month with the most sunshine is August (Average sunshine: 10h and 48min).
The month with the least sunshine is December (Average sunshine: 4h and 36min).
Average sunshine days in September
Dennis, MA
- Average sunshine days in September: 18.5 days
The month with the most sunshine days is September (18.5 days).
The month with the least sunshine days is February (14.8 days).
Average UV index in September
Dennis, 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
Dennis, MA
- Average cloud cover in September: 31
The months with the most cloud cover are February and December (Cloud cover 50).
The month with the least cloud cover is August (Cloud cover 27).
Average visibility in September
Dennis, 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).
Dennis, Massachusetts, USA
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