August 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 August

The last month of the summer, August, is another warm month in Boston, Massachusetts, with an average temperature fluctuating between 64°F (17.8°C) and 80.4°F (26.9°C).

Temperature

In Boston, the average high-temperature in August is essentially the same as in July - a still warm 80.4°F (26.9°C). In August, in Boston, the average low-temperature is 64°F (17.8°C).

Humidity

In August, the average relative humidity in Boston is 72%.

Rainfall

In Boston, during August, the rain falls for 11.7 days and regularly aggregates up to 1.61" (41mm) of precipitation. Throughout the year, in Boston, there are 141.4 rainfall days, and 27.2" (691mm) of precipitation is accumulated.

Snowfall

June through September are months without snowfall in Boston.

Ocean temperature

August is the month with the warmest seawater, with an average ocean temperature of 68°F (20°C).
Note: 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).

Daylight

In Boston, the average length of the day in August is 13h and 51min.
On the first day of August, sunrise is at 5:37 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 6:08 am and sunset at 7:20 pm EDT.

Sunshine

With an average of 10.5h of sunshine, August has the most sunshine of the year in Boston.

UV index

The months with the highest UV index are June through August, with an average maximum UV index of 6. A UV Index estimate of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for the ordinary person.
Note: The average daily UV index of 6 in August transform into the following instructions:
Take precautions and utilize sun safety practices. Protection against skin and eye damage is required. The Sun's UV radiation is most powerful between 10 a.m. and 4 p.m. To the extent possible, limit exposure to the direct sun during these hours. On bright days sunglasses that block both UVA and UVB rays should be worn. A hat with a wide brim is extremely helpful, as it can prevent roughly 50% of UV radiation from reaching the eyes.
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FAQ

What is the average humidity in August in Boston?

The average relative humidity in August in Boston is 72%.

How much does it rain in Boston in August?

In Boston, in August, it is raining for 11.7 days, with typically 1.61" (41mm) of accumulated precipitation.

When it does not snow in Boston?

June through September are months without snowfall.

What month is the ocean warmest in Boston?

With an average ocean temperature of 68°F (20°C), August is the month with the warmest seawater.

How cold is the water in August in Boston?

In Boston, Massachusetts, in August, the average water temperature 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).

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

In Boston, the average day length in August is 13h and 51min.

When are sunrise and sunset in August in Boston?

In August, on the first day of the month, sunrise is at 5:37 am and sunset at 8:04 pm. On the last day of the month, sunrise is at 6:08 am and sunset at 7:20 pm EDT.

What month has the most sunshine in Boston?

With an average of 10.5h of sunshine, August has the most sunshine of the year.

How many hours of sunshine does Boston have in August?

In August, the average sunshine duration in Boston is 10.5h.

When is the highest UV index in Boston?

The months with the highest UV index are June through August, with an average maximum UV index of 6.

What is the UV index intensity in August in Boston?

In August, the average daily maximum UV index is 6. A UV Index estimate of 6 to 7 represents a high health risk from exposure to Sun's UV rays.
Average humidity
Average rainfall days
Average snowfall
Average snowfall days
Average sunshine days
Average UV index
Average cloud cover
Average visibility

Average temperature in August
Boston, MA

Average temperature in August - Boston, MA
  • Average high temperature in August: 80.4°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 August: 64°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).

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Average pressure in August
Boston, MA

Average pressure in August - Boston, MA
  • Average pressure in August: 29.98"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).

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Average wind speed in August
Boston, MA

Average wind speed in August - Boston, MA
  • Average wind speed in August: 6.2mph

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).

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Average humidity in August
Boston, MA

Average humidity in August - Boston, MA
  • Average humidity in August: 72%

The month with the highest relative humidity is February (77%).
The month with the lowest relative humidity is April (69%).

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Average rainfall in August
Boston, MA

Average rainfall in August - Boston, MA
  • Average rainfall in August: 1.61"

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").

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Average rainfall days in August
Boston, MA

Average rainfall days in August - Boston, MA
  • Average rainfall days in August: 11.7 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).

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Average snowfall in August
Boston, MA

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

The month with the highest snowfall is February (4.72").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in August
Boston, MA

Average snowfall days in August - Boston, MA
  • Average snowfall days in August: 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).

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Average sea temperature in August
Boston, MA

Average sea temperature in August - Boston, MA
  • Average sea temperature in August: 67.9°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).

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

Average daylight in August / Average sunshine in August - Boston, MA
  • Average daylight in August: 13h and 51min

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 August: 10h and 30min

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).

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Average sunshine days in August
Boston, MA

Average sunshine days in August - Boston, MA
  • Average sunshine days in August: 17 days

The month with the most sunshine days is September (17.7 days).
The month with the least sunshine days is April (13 days).

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Average UV index in August
Boston, MA

Average UV index in August - Boston, MA
  • Average UV index in August: 6

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).

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Average cloud cover in August
Boston, MA

Average cloud cover in August - Boston, MA
  • Average cloud cover in August: 32

The month with the most cloud cover is March (Cloud cover 51).
The month with the least cloud cover is August (Cloud cover 32).

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Average visibility in August
Boston, MA

Average visibility in August - Boston, MA
  • Average visibility in August: 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).

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