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
September ushers in a minor alteration in Chelsea's climate, with the average high-temperature moving from August's moderately hot 80.4°F (26.9°C) to a pleasant 72.7°F (22.6°C). During the month of September, Chelsea's nighttime temperature lowers to an average of 57.4°F (14.1°C).Humidity
The average relative humidity in September in Chelsea is 75%.Rainfall
September is the month with the least rainfall in Chelsea. Rain falls for 10 days and accumulates 1.26" (32mm) of precipitation.Snowfall
In Chelsea, snow does not fall in June through September.Ocean temperature
In Chelsea, in September, the average water temperature is 64.8°F (18.2°C).Note: Swimming is not a pleasurable activity for most people when the water temperature is 64.8°F (18.2°C). Breathing control gets harder as the water temperature drops from 69.8°F (21°C) to 59°F (15°C).
Daylight
The average length of the day in September is 12h and 28min.On the first day of September, sunrise is at 6:10 am and sunset at 7:17 pm. On the last day of the month, sunrise is at 6:40 am and sunset at 6:26 pm EDT.
Sunshine
The average sunshine in September is 8.4h.UV index
In September, the average daily maximum UV index is 4. A UV Index reading of 3 to 5 represents a medium vulnerability from exposure to the Sun's UV radiation for average individuals.Note: The daily high UV index of 4 in September translates into this advice:
Be careful. Light complexion individuals might get burns in fewer than 30 minutes. Solar radiation is at its peak intensity during midday, so it's advisable to stay indoors or in the shade. Wearing a wide-brim hat can block approximately 50% of UV radiation, protecting the eyes.
Frequently asked questions
What are the temperatures in Chelsea in September?
What is the average humidity in September in Chelsea?
What is the driest month in Chelsea?
How much does it rain in Chelsea in September?
When it does not snow in Chelsea?
Does it snow in Chelsea in September?
What is the ocean temperature in September in Chelsea?
How many hours of daylight does Chelsea have in September?
When is the sunrise / sunset in September in Chelsea?
How many hours of sunshine does Chelsea have in September?
What is the UV index reading in September in Chelsea?
Average temperature in September
Chelsea, MA
- Average high temperature in September: 72.7°F
The warmest month (with the highest average high temperature) is July (81.7°F).
The month with the lowest average high temperature is January (34.2°F).
- Average low temperature in September: 57.4°F
The month with the highest average low temperature is July (64.9°F).
The coldest month (with the lowest average low temperature) is January (22.6°F).
Average pressure in September
Chelsea, 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
Chelsea, MA
- Average wind speed in September: 6.8mph
The windiest month (with the highest average wind speed) is January (9.9mph).
The calmest month (with the lowest average wind speed) is August (6.2mph).
Average humidity in September
Chelsea, MA
- Average humidity in September: 75%
The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (69%).
Average rainfall in September
Chelsea, MA
- Average rainfall in September: 1.26"
The wettest months (with the highest rainfall) are March, April and December (2.91").
The driest month (with the least rainfall) is September (1.26").
Average rainfall days in September
Chelsea, MA
- Average rainfall days in September: 10 days
The month with the highest number of rainy days is May (15.3 days).
The month with the least rainy days is January (7.9 days).
Average snowfall in September
Chelsea, MA
- Average snowfall in September: 0"
The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").
Average snowfall days in September
Chelsea, MA
- Average snowfall days in September: 0 days
The months with the highest number of snowfall days are January and February (7.6 days).
The months with the least snowfall days are June, July, August and September (0 days).
Average sea temperature in September
Chelsea, MA
- Average sea temperature in September: 64.8°F
The best month for swimming (with the highest average sea temperature) is August (67.9°F).
The coldest month (with the lowest average sea temperature) is February (38.1°F).
Average daylight in September /
Average sunshine in September
Chelsea, 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 6min).
- Average sunshine in September: 8h and 2min
The month with the most sunshine is August (Average sunshine: 10h and 30min).
The month with the least sunshine is February (Average sunshine: 4h and 36min).
Average sunshine days in September
Chelsea, MA
- Average sunshine days in September: 17.7 days
The month with the most sunshine days is September (17.7 days).
The month with the least sunshine days is April (13 days).
Average UV index in September
Chelsea, MA
- 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
Chelsea, MA
- Average cloud cover in September: 37
The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 32).
Average visibility in September
Chelsea, 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).
Chelsea, Massachusetts, USA
Weather forecast for your location
2. Allow the app to use your location
