August weather forecast
Chelmsford, MA

Weather in August

August, the last month of the summer in Chelmsford, is also a moderately hot month, with an average temperature ranging between max 80.6°F (27°C) and min 62.2°F (16.8°C).

Temperature

In August, the average high-temperature is almost the same as in July - a still moderately hot 80.6°F (27°C). The average low-temperature, in Chelmsford, is 62.2°F (16.8°C).

Heat index

In August, the average heat index is calculated to be 84.2°F (29°C). Exhaustion is likely with prolonged exposure and activity. Sustaining activity may result in heat cramps.
Take into consideration that the heat index values are calculated for shade and light wind conditions. Exposure to direct sunshine can increase heat index values by up to 15 Fahrenheit (8 Celsius) degrees.
Note: The heat index, also known as 'apparent temperature', 'felt air temperature', 'real feel', or 'feels like', is a measure of how hot it feels when the actual air humidity is factored in. Additional factors like activity, metabolic differences, differences in body mass, height, and shape, and wind affect individual temperature impact. Bear in mind that direct sunshine exposure increases weather impact, and may raise heat index by up to 15 Fahrenheit (8 Celsius) degrees. Heat index values are especially crucial for babies and toddlers. Children are often less aware of the need to rest and re-hydrate. Thirst is a late sign of dehydration - it is vital to remain hydrated, particularly during prolonged physical activities.

Humidity

The average relative humidity in August is 74%.

Rainfall

In August, the rain falls for 13.1 days. Throughout August, 1.93" (49mm) of precipitation is accumulated. In Chelmsford, during the entire year, the rain falls for 145.9 days and collects up to 27.48" (698mm) of precipitation.

Snowfall

In Chelmsford, Massachusetts, snow does not fall in June through September.

Daylight

In August, the average length of the day is 13h and 52min.
On the first day of the month, sunrise is at 5:37 am and sunset at 8:06 pm. On the last day of August, in Chelmsford, sunrise is at 6:09 am and sunset at 7:22 pm EDT.

Sunshine

With an average of 10.6h of sunshine, August has the most sunshine of the year.

UV index

The months with the highest UV index in Chelmsford, Massachusetts, are June through August, with an average maximum UV index of 6. A UV Index reading of 6 to 7 represents a high health vulnerability from unsafe exposure to UV radiation for the average person.
Note: In August, the average maximum UV index of 6 translate into the following recommendations:
Take precautions against overexposure. Protection against sun damage is needed. 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. A wide-brim hat offers excellent sun protection for the eyes, ears, face, and neck. Sunglasses with UVA and UVB protection significantly reduce eye damage from sun exposure. Tightly woven, loose-fitting clothes provide additional protection from the Sun.
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FAQ

What is the temperature in August in Chelmsford?

In August, in Chelmsford, Massachusetts, the average high-temperature is 80.6°F (27°C), and the average low-temperature is 62.2°F (16.8°C). The average heat index (a.k.a. 'apparent temperature', 'real feel'), which represents the influence of relative humidity on air temperature, in August is calculated to be 84.2°F (29°C).

What is the average humidity in August in Chelmsford?

In August, the average relative humidity in Chelmsford is 74%.

How many days does it rain in August in Chelmsford?

In Chelmsford, in August, during 13.1 rainfall days, 1.93" (49mm) of precipitation is typically accumulated.

When it does not snow in Chelmsford?

In Chelmsford, snow does not fall in June through September.

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

The average day length in August is 13h and 52min.

What time are sunrise and sunset in August in Chelmsford?

On the first day of August in Chelmsford, Massachusetts, sunrise is at 5:37 am and sunset at 8:06 pm. On the last day of the month, sunrise is at 6:09 am and sunset at 7:22 pm EDT.

What month has the most sunshine in Chelmsford?

With an average of 10.6h of sunshine, August has the most sunshine of the year in Chelmsford, Massachusetts.

How long on average sun shines in August in Chelmsford?

In August, the average sunshine duration in Chelmsford, Massachusetts, is 10.6h.

When is the highest UV index in Chelmsford?

June through 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 Chelmsford?

In Chelmsford, Massachusetts, the average daily maximum UV index in August is 6. A UV Index estimate of 6 to 7 represents a high health threat from unsafe 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
Chelmsford, MA

Average temperature in August - Chelmsford, MA
  • Average high temperature in August: 80.6°F

The warmest month (with the highest average high temperature) is July (82.2°F).
The month with the lowest average high temperature is January (32.5°F).

  • Average low temperature in August: 62.2°F

The month with the highest average low temperature is July (63.1°F).
The coldest month (with the lowest average low temperature) is January (19.9°F).

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Average pressure in August
Chelmsford, MA

Average pressure in August - Chelmsford, MA
  • Average pressure in August: 29.97"Hg

The month with the highest atmospheric pressure is November (30.07"Hg).
The month with the lowest atmospheric pressure is June (29.92"Hg).

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Average wind speed in August
Chelmsford, MA

Average wind speed in August - Chelmsford, MA
  • Average wind speed in August: 5.5mph

The windiest month (with the highest average wind speed) is January (8.8mph).
The calmest months (with the lowest average wind speed) are July and August (5.5mph).

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Average humidity in August
Chelmsford, MA

Average humidity in August - Chelmsford, MA
  • Average humidity in August: 74%

The month with the highest relative humidity is February (80%).
The month with the lowest relative humidity is April (70%).

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Average rainfall in August
Chelmsford, MA

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

The wettest month (with the highest rainfall) is December (2.87").
The driest month (with the least rainfall) is September (1.46").

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Average rainfall days in August
Chelmsford, MA

Average rainfall days in August - Chelmsford, MA
  • Average rainfall days in August: 13.1 days

The month with the highest number of rainy days is May (15.6 days).
The month with the least rainy days is February (6.9 days).

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Average snowfall in August
Chelmsford, MA

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

The month with the highest snowfall is February (5.98").
The months with the least snowfall are June, July, August and September (0").

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Average snowfall days in August
Chelmsford, MA

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

The month with the highest number of snowfall days is February (8.3 days).
The months with the least snowfall days are June, July, August and September (0 days).

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

Average daylight in August / Average sunshine in August - Chelmsford, MA
  • Average daylight in August: 13h and 52min

The month with the longest days is June (Average daylight: 15h and 16min).
The month with the shortest days is December (Average daylight: 9h and 7min).

  • Average sunshine in August: 10h and 36min

The month with the most sunshine is August (Average sunshine: 10h and 36min).
The month with the least sunshine is February (Average sunshine: 4h and 42min).

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Average sunshine days in August
Chelmsford, MA

Average sunshine days in August - Chelmsford, MA
  • Average sunshine days in August: 15.9 days

The month with the most sunshine days is November (17.4 days).
The month with the least sunshine days is May (13.6 days).

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Average UV index in August
Chelmsford, MA

Average UV index in August - Chelmsford, 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
Chelmsford, MA

Average cloud cover in August - Chelmsford, MA
  • Average cloud cover in August: 31

The month with the most cloud cover is March (Cloud cover 49).
The month with the least cloud cover is August (Cloud cover 31).

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Average visibility in August
Chelmsford, MA

Average visibility in August - Chelmsford, MA
  • Average visibility in August: 6mi

The months with the highest visibility are January, March, April, May, June, July, August, September, October, November and December (6mi).
The month with the lowest visibility is February (5mi).

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