August weather forecast and climate
Boston, MA

A beautiful natural park with the George Washington Monument in Boston, Massachusetts, with a sneak view of the city skyscrapers
A beautiful natural park with the George Washington Monument in Boston, Massachusetts, with a sneak view of the city skyscrapers
August in Boston is a moderately dry month, receiving mildly low rainfall of approximately 3.4" (86.4mm), collected from an average of nine days.
The mercury is in the high range of 64.6°F (18.1°C) and 79.5°F (26.4°C), with occasional days when the temperature rises as high as 86°F (30°C) or more.
There are up to ten sunshine hours per day, and it becomes essential to cover up while in the sun since the UV index is at its highest. The average sea temperature in August is 64.4°F (18°C), the highest recording of the year. Swimming and other sea activities become vibrant, even with the mildly cool water, as the water temperature of above 64.4°F (18°C) is rare.
Being the peak of summer, tourists continue to enjoy the festivities in Boston until late into the evening, appreciative of the extended daylight hours.

What is the temperature in August in Boston?

The average high-temperature, in August, is 79.5°F (26.4°C), while the average low-temperature is 64.6°F (18.1°C).

How many days does it rain in August in Boston?

In Boston, during August, the rain falls for 9.4 days and regularly aggregates up to 3.4" (85.1mm) of precipitation.

What month is the sea warmest in Boston?

Month with the warmest seawater in Boston, Massachusetts, is August, with an average sea temperature of 68°F (20°C). Swimming in 68°F (20°C) is not enjoyable for the majority. Controlling breathing becomes progressively more difficult as surface water temperature decreases below 69.8°F (21°C).

What is the sea water temperature in August in Boston?

The average seawater temperature, in August, in Boston, is 68°F (20°C). For swimming, a surface water temperature of 68°F (20°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).
Average temperature in August - Boston, MA
  • Average high temperature in August: 26.4°C

The warmest month (with the highest average high temperature) is July (27.4°C).
The month with the lowest average high temperature is January (2.1°C).

  • Average low temperature in August: 18.1°C

The month with the highest average low temperature is July (18.6°C).
The coldest month (with the lowest average low temperature) is January (-5.4°C).

Average humidity in August - Boston, MA
  • Average humidity in August: 70.8%

The month with the highest relative humidity is September (71.8%).
The month with the lowest relative humidity is February (62%).

Average rainfall in August - Boston, MA
  • Average rainfall in August: 85.1mm

The wettest month (with the highest rainfall) is March (109.7mm).
The driest month (with the lowest rainfall) is February (82.6mm).

Average rainfall days in August - Boston, MA
  • Average rainfall days in August: 9.4 days

The month with the highest number of rainy days is May (12 days).
The month with the lowest number of rainy days is September (8.6 days).

Average snowfall in August - Boston, MA
  • Average snowfall in August: 0mm

The month with the highest snowfall is January (327.7mm).
Months with the lowest snowfall are May, June, July, August, September and October (0mm).

Average snowfall days in August - Boston, MA
  • Average snowfall days in August: 0 days

The month with the highest number of snowfall days is January (6.7 days).
Months with the lowest number of snowfall days are May, June, July, August and September (0 days).

Average sea temperature in August - Boston, MA
  • Average sea temperature in August: 20°C

The best month for swimming (with the highest average sea temperature) is August (20°C).
The coldest month (with the lowest average sea temperature) is February (3.4°C).

Average daylight in August / Average sunshine in August - Boston, MA
  • Average daylight in August: 13.8h

The month with the longest days is June (Average daylight: 15.2h).
The month with shortest days is December (Average daylight: 9.1h).

  • Average sunshine in August: 8.9h

The month with most sunshine is July (Average sunshine: 9.7h).
The month with least sunshine is December (Average sunshine: 4.6h).

Average UV index in August - Boston, MA
  • Average UV index in August: 8

Months with the highest UV index are June, July and August (UV index 8).
Months with the lowest UV index are January and December (UV index 1).

deutscheenglishespañolрусский中文