August weather forecast
Nantucket, MA

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Beautiful homes built on the water overlooking the boats on the water below, in Nantucket, Massachusetts
Beautiful homes built on the water overlooking the boats on the water below, in Nantucket, Massachusetts

Weather in August

August sees Nantucket, Massachusetts, continue its summer indulgence. While the average high temperature is comparable to July, the lowest level reaches a high of 68.7°F (20.4°C). Despite the residual heat, August sees the beginning of a gentle cool down in evening temperatures, signaling the onset of autumn. A slight decrease in sunshine hours coupled with a marginal increase in rainfall provides respite from the summer sun. Overall, August is when Nantucket offers the last full touch of summery delight before transitioning into fall.

Temperature

August temperatures tend to peak at an average high of 72.1°F (22.3°C) and dip to a low of 68.7°F (20.4°C).

Humidity

The average relative humidity in August is 82%.

Rainfall

In Nantucket, in August, during 12.9 rainfall days, 1.93" (49mm) of precipitation is typically accumulated. In Nantucket, during the entire year, the rain falls for 153 days and collects up to 26.61" (676mm) of precipitation.

Snowfall

April through October are months without snowfall in Nantucket.

Ocean temperature

With an average ocean temperature of 67.6°F (19.8°C), August is the month with the warmest seawater.
Note: Swimming is not an enjoyable activity for the majority when the water is at 67.6°F (19.8°C). The difficulty of controlling breathing increases as the temperature dips from 69.8°F (21°C) to 59°F (15°C).

Daylight

In Nantucket, the average length of the day in August is 13h and 47min.
On the first day of the month, sunrise is at 5:36 am and sunset at 7:56 pm. On the last day of August, sunrise is at 6:06 am and sunset at 7:14 pm EDT.

Sunshine

July and August, with an average of 10.7h of sunshine, are months with the most sunshine.

UV index

July and August, with an average maximum UV index of 6, are months with the highest UV index. A UV Index of 6 to 7 symbolizes a high health hazard from unprotected exposure to Sun's UV rays for the average person.
Note: The UV index of 6 during August leads to these advisories:
Embrace precautions and observe sun safety norms. Evasion of sunburn is a necessity. Avoid direct exposure to the Sun between 10 a.m. and 4 p.m., the peak period for UV radiation, noting that objects like parasols or canopies might not offer complete sun protection. For holistic sun protection encompassing the eyes, ears, face, and neck, a wide-brim hat is key.

Frequently asked questions

What is the warmest month?

August, with its high-temperature average of 72.1°F (22.3°C) and a low-temperature average of 68.7°F (20.4°C), is the warmest month.

What are August temperatures?

In Nantucket, 72.1°F (22.3°C) is the average high-temperature and 68.7°F (20.4°C) is the average low-temperature during August.

What is the average humidity in August?

The average relative humidity in August is 82%.

How many days does it rain in August?

In Nantucket, in August, during 12.9 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

When it does not snow?

In Nantucket, Massachusetts, snow does not fall in April through October.

What is the month with the warmest ocean?

With an average ocean temperature of 67.6°F (19.8°C), August is the month with the warmest seawater.

What is the ocean temperature in August?

In August, the average ocean temperature is 67.6°F (19.8°C). For swimming, a surface water temperature of 67.6°F (19.8°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 Nantucket, the average day length in August is 13h and 47min.

When are sunrise and sunset in August?

On the first day of August, sunrise is at 5:36 am and sunset at 7:56 pm. On the last day of the month, sunrise is at 6:06 am and sunset at 7:14 pm EDT.

What is the month with the most sunshine?

The months with the most sunshine are July and August, with an average of 10.7h of sunshine.

How many hours of sunshine does Nantucket have in August?

The average sunshine duration in August is 10.7h.

What are the months with the highest UV index?

July and August, with an average maximum UV index of 6, are months with the highest UV index.

What is the UV index reading in August?

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

Average temperature in August
Nantucket, MA

Average temperature in August - Nantucket, MA
  • Average high temperature in August: 72.1°F

The warmest month (with the highest average high temperature) is August (72.1°F).
The month with the lowest average high temperature is February (39.7°F).

  • Average low temperature in August: 68.7°F

The month with the highest average low temperature is August (68.7°F).
The coldest month (with the lowest average low temperature) is February (32.5°F).

Average pressure in August
Nantucket, MA

Average pressure in August - Nantucket, 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 (29.94"Hg).

Average wind speed in August
Nantucket, MA

Average wind speed in August - Nantucket, MA
  • Average wind speed in August: 11.8mph

The windiest month (with the highest average wind speed) is January (18.5mph).
The calmest month (with the lowest average wind speed) is August (11.8mph).

Average humidity in August
Nantucket, MA

Average humidity in August - Nantucket, MA
  • Average humidity in August: 82%

The month with the highest relative humidity is July (86%).
The months with the lowest relative humidity are January, November and December (75%).

Average rainfall in August
Nantucket, MA

Average rainfall in August - Nantucket, MA
  • Average rainfall in August: 1.93"

The wettest month (with the highest rainfall) is October (3.27").
The driest month (with the least rainfall) is November (1.77").

Average rainfall days in August
Nantucket, MA

Average rainfall days in August - Nantucket, MA
  • Average rainfall days in August: 12.9 days

The month with the highest number of rainy days is May (14.3 days).
The month with the least rainy days is February (9.2 days).

Average snowfall in August
Nantucket, MA

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

The month with the highest snowfall is January (1.06").
The months with the least snowfall are April, May, June, July, August, September and October (0").

Average snowfall days in August
Nantucket, MA

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

The month with the highest number of snowfall days is January (5.8 days).
The months with the least snowfall days are May, June, July, August, September and October (0 days).

Average sea temperature in August
Nantucket, MA

Average sea temperature in August - Nantucket, MA
  • Average sea temperature in August: 67.6°F

The best month for swimming (with the highest average sea temperature) is August (67.6°F).
The coldest month (with the lowest average sea temperature) is February (37.9°F).

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

Average daylight in August / Average sunshine in August - Nantucket, MA
  • Average daylight in August: 13h and 5min

The month with the longest days is June (Average daylight: 15h and 6min).
The month with the shortest days is December (Average daylight: 9h and 18min).

  • Average sunshine in August: 10h and 4min

The months with the most sunshine are July and August (Average sunshine: 10h and 42min).
The month with the least sunshine is December (Average sunshine: 4h and 18min).

Average sunshine days in August
Nantucket, MA

Average sunshine days in August - Nantucket, MA
  • Average sunshine days in August: 16.5 days

The month with the most sunshine days is August (16.5 days).
The month with the least sunshine days is January (11.3 days).

Average UV index in August
Nantucket, MA

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

The months with the highest UV index are July and August (UV index 6).
The months with the lowest UV index are January, February, March and December (UV index 2).

Average cloud cover in August
Nantucket, MA

Average cloud cover in August - Nantucket, MA
  • Average cloud cover in August: 27

The month with the most cloud cover is December (Cloud cover 54).
The month with the least cloud cover is August (Cloud cover 27).

Average visibility in August
Nantucket, MA

Average visibility in August - Nantucket, 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).

Nantucket, Massachusetts, USA

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