September weather forecast
Boston, MA

A beautiful natural park with the George Washington Monument in Boston, Massachusetts
A beautiful natural park with the George Washington Monument in Boston, Massachusetts

Weather in September

The first month of the autumn, September, is also an agreeable month in Boston, Massachusetts, with an average temperature ranging between max 72.7°F (22.6°C) and min 57.4°F (14.1°C).

Temperature

In Boston, the average high-temperature in September marginally drops from a warm 80.4°F (26.9°C) in August to a pleasant 72.7°F (22.6°C). In Boston, the average low-temperature is 57.4°F (14.1°C).

Humidity

The average relative humidity in September in Boston is 75%.

Rainfall

September is the month with the least rainfall in Boston, Massachusetts. Rain falls for 10 days and accumulates 1.26" (32mm) of precipitation.

Snowfall

June through September are months without snowfall.

Ocean temperature

In September, the average ocean temperature is 64.8°F (18.2°C).
Note: For swimming, a surface water temperature of 64.8°F (18.2°C) is not enjoyable for the majority. It is not considered safe, as controlling breathing becomes progressively more difficult as water temperature decreases below 69.8°F (21°C).

Daylight

In September, the average length of the day in Boston is 12h and 28min.
On the first day of the month, sunrise is at 6:09 am and sunset at 7:18 pm. On the last day of September, in Boston, Massachusetts, sunrise is at 6:40 am and sunset at 6:27 pm EDT.

Sunshine

In September, the average sunshine in Boston is 8.4h.

UV index

In Boston, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate health risk from unprotected exposure to Sun's UV rays for the ordinary person.
Note: The average daily UV index of 4 in September transform into the following instructions:
Take precautions. Light skin individuals may get burned in less than 30 minutes. The solar radiation is most powerful near the mid-day, so the exposure to the direct Sun should be reduced accordingly. Sun-protective clothing, a long-sleeved shirt and pants, a wide-brimmed hat, and UVA and UVB-blocking sunglasses are particularly helpful in blocking UV radiation's harmful effects.
[Resources]

FAQ

What is the average humidity in September in Boston?

The average relative humidity in September is 75%.

What is the driest month in Boston?

The month with the least rainfall in Boston, Massachusetts, is September, when the rain falls for 10 days and typically collects 1.26" (32mm) of precipitation.

How many days does it rain in September in Boston?

In Boston, Massachusetts, in September, it is raining for 10 days, with typically 1.26" (32mm) of accumulated precipitation.

When it does not snow in Boston?

June through September are months without snowfall in Boston.

Does it snow in Boston in September?

In Boston, in September, it doesn't snow. In October, it regularly snows.

What is the ocean temperature in September in Boston?

In September, the average ocean temperature in Boston is 64.8°F (18.2°C). For most, swimming in 64.8°F (18.2°C) is not an enjoyable activity. Furthermore, controlling your breathing becomes progressively more difficult as the water temperature decreases from 69.8°F (21°C) to 59°F (15°C).

What is the average length of the day in September in Boston?

In Boston, the average day length in September is 12h and 28min.

What time are sunrise and sunset in September in Boston?

In September, on the first day of the month, sunrise is at 6:09 am and sunset at 7:18 pm. On the last day of the month, in Boston, Massachusetts, sunrise is at 6:40 am and sunset at 6:27 pm EDT.

How long on average sun shines in September in Boston?

In Boston, Massachusetts, the average sunshine duration in September is 8.4h.

What is the UV index reading in September in Boston?

In Boston, Massachusetts, the average daily maximum UV index in September is 4. A UV Index value of 3 to 5 symbolizes a moderate vulnerability from exposure to the Sun's UV radiation.

Average temperature in September
Boston, MA

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).

[Resources]

Average pressure in September
Boston, MA

Average pressure in September - Boston, MA
  • Average pressure in September: 30.05"

The month with the highest atmospheric pressure is November (30.06").
The month with the lowest atmospheric pressure is June (29.93").

[Resources]

Average wind speed in September
Boston, MA

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).

[Resources]

Average humidity in September
Boston, MA

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%).

[Resources]

Average rainfall in September
Boston, MA

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").

[Resources]

Average rainfall days in September
Boston, MA

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).

[Resources]

Average snowfall in September
Boston, MA

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").

[Resources]

Average snowfall days in September
Boston, MA

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).

[Resources]

Average sea temperature in September
Boston, MA

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).

[Resources]

Average daylight in September /
Average sunshine in September
Boston, MA

Average daylight in September / Average sunshine in September - Boston, MA
  • Average daylight in September: 12h and 28min

The month with the longest days is June (Average daylight: 15h and 14min).
The month with the shortest days is December (Average daylight: 9h and 8min).

  • Average sunshine in September: 8.4h

The month with the most sunshine is August (Average sunshine: 10.5h).
The month with the least sunshine is February (Average sunshine: 4.6h).

[Resources]

Average sunshine days in September
Boston, MA

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).

[Resources]

Average UV index in September
Boston, MA

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).

[Resources]

Average cloud cover in September
Boston, MA

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).

[Resources]

Average visibility in September
Boston, MA

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).

[Resources]

Weather forecast for your location

1. Click Locate me button
2. Allow the app to use your location
* you will be automatically redirected to the weather forecast for your location