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
Boston experiences a moderate temperature shift at the start of September, with average high-temperatures adjusting a bit from a moderately hot 80.4°F (26.9°C) in August to an agreeable 72.7°F (22.6°C). Boston records an average nighttime low of 57.4°F (14.1°C) in September.Humidity
In September, the average relative humidity in Boston, Massachusetts, is 75%.Rainfall
September is the month with the least rainfall. Rain falls for 10 days and accumulates 1.26" (32mm) of precipitation.Snowfall
June through September are months without snowfall.Ocean temperature
In Boston, the average seawater temperature in September is 64.8°F (18.2°C).Note: Most people do not enjoy swimming in water of 64.8°F (18.2°C). Breathing control becomes harder as the temperature descends from 69.8°F (21°C) to 59°F (15°C).
Daylight
In Boston, the average length of the day in September is 12h and 28min.On the first day of September in Boston, 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 estimate of 3 to 5 represents a medium vulnerability from unprotected exposure to Sun's UV rays for average individuals.Note: The maximum UV index of 4 during September translates into these guidelines:
Heed the precautions - It is counselled to guard against solar damage. For skin protection, it's recommended to minimize Sun exposure during its peak hours around midday. By wearing a generously brimmed hat, you can cut UV radiation exposure significantly.
Frequently asked questions
What are September temperatures in Boston?
What is the average humidity in September in Boston?
What is the driest month in Boston?
How much does it rain in Boston in September?
When it does not snow in Boston?
Does it snow in Boston in September?
How cold is the water in September in Boston?
What is the average length of the day in September in Boston?
When are sunrise and sunset in September in Boston?
How long on average sun shines in September in Boston?
What is the UV index reading in September in Boston?
Average temperature in September
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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
Boston, 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).
Boston, Massachusetts, USA
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