September weather forecastDennis, MA
September
Weather in September
The first month of the autumn, September, is still a comfortable month in Dennis, Massachusetts, with temperature in the range of an average high of 67.5°F (19.7°C) and an average low of 62.8°F (17.1°C).Temperature
Dennis signifies an average high-temperature of a comfortable 67.5°F (19.7°C) in September, closely mirroring the 72.5°F (22.5°C) of August. Dennis experiences a steady nighttime temperature of 62.8°F (17.1°C) throughout the month of September.Humidity
In September, the average relative humidity is 79%.Rainfall
In Dennis, in September, it is raining for 9.4 days, with typically 1.1" (28mm) of accumulated precipitation. Throughout the year, there are 129.6 rainfall days, and 13.94" (354mm) of precipitation is accumulated.Snowfall
May through November are months without snowfall.Daylight
The average length of the day in September 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
The average sunshine in September is 8.8h.UV index
In Dennis, Massachusetts, the average daily maximum UV index in September is 4. A UV Index of 3 to 5 symbolizes a medium vulnerability from unsafe exposure to UV radiation for average individuals.Note: A daily high UV index of 4 in September leads to these guidelines:
Stay alert. Light-skinned people could suffer burns in less than 30 minutes. It's crucial to reduce time in the direct Sun around mid-day due to the intense solar radiation. Outfit yourself in sun-safe attire, like long sleeves, pants, a hat, and UV-blocking sunglasses.
Published by: Weather U.S. | About Us
Data Sources | Weather Forecasting & Climate
Frequently asked questions
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 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 48min
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).
