Boston, MA weather in August
In August, Boston sees highs around 80°F and lows around 65°F: warm and often humid, with some rain. Rain falls on about 9 days. It is one of the warmest months in Boston. Good for outdoor plans.
- Normal high
- 80°F
- Normal low
- 65°F
- Wet days
- 9
- 3.2 in total
- Muggy days
- 9
- dew point 65°F+
How August changes from start to finish
| August 1 | August 31 | |
|---|---|---|
| Normal high | 82°F | 78°F |
| Normal low | 66°F | 63°F |
| Chance of a wet day | 31% | 28% |
| Sunrise / sunset | 5:36 am / 8:04 pm | 6:08 am / 7:20 pm |
| Daylight | 14.4 h | 13.2 h |
Chance of a wet day: average for the first and last 7 days of the month. Times are local clock time (Eastern Time).
A typical August day
- 6 am68°Fdew point 61°F
- 9 am74°Fdew point 61°F
- Noon77°Fdew point 61°F
- 3 pm77°Fdew point 61°F
- 6 pm75°Fdew point 61°F
- 9 pm71°Fdew point 62°F
NOAA hourly normals (local standard time) from Boston Logan Intl Airport (3 mi away); average wind 10 mph; clear or few clouds in 28% of daytime hours, mostly cloudy or overcast in 47%.
What kind of days to expect
- Comfortable dayshigh 65-80°F and dew point under 60°F8 of 31
- Beach dayshigh 80-95°F, under 0.05 in of rain, afternoon wind under 15 mph11 of 31
- Hot dayshigh 90°F or more4 of 31
- Muggy daysdaily mean dew point 65°F or more9 of 31
- Wet daysat least 0.01 in of rain or melted snow9 of 31
- Notable rainat least 0.10 in5 of 31
- Freezing nightslow 32°F or below0 of 31
- Snow on the groundsnow depth 1 in or more0 of 31
Average days per August, counted from daily records for each year 1991-2020.
Rain in August
Normal precipitation is 3.2 in; a dry August brings about 1.8 in and a wet one about 4.3 in (25th and 75th percentiles). About 2 days bring half an inch or more, and about 1 an inch or more.
How August varies from year to year
- Warmest August, 1991-20202018: average high 85°F
- Coolest August2008: average high 77°F
- Wettest August2011: 7.7 in
- Driest August2007: 0.7 in
- Highest reading101°F (August 14, 2002)
- Lowest reading55°F (August 22, 2007)
From the station's daily records with NOAA quality flags removed; most recent date shown when a reading repeats.
August compared with July and September
| July | August | September | |
|---|---|---|---|
| Normal high | 82°F | 80°F | 73°F |
| Normal low | 66°F | 65°F | 58°F |
| Wet days | 9 | 9 | 9 |
| Comfortable days | 6 | 8 | 15 |
| Daylight | 14.9 h | 13.8 h | 12.5 h |
Highs change by -2°F from July and -7°F into September.
Nearby alternatives in August
- Cooler: Lake Placid, NY198 mi · high 73°F · 13 wet days
How Boston ranks in August
- Normal high305th warmest of 378 cities; 6th of 9 in Massachusetts
- Wet days193rd driest of 378
- Comfortable days93rd most of 341
What to pack for Boston in August
- A rain jacket or umbrella – rain on about 9 days
- A swimsuit – about 11 beach days
Heating and cooling
August has 5 heating degree days and 245 cooling degree days (base 65°F), 4% of the year's total heating and cooling demand.
Questions
How hot is Boston in August?
The normal high is 80°F and the normal low is 65°F. From 1991 to 2020 the hottest August reading was 101°F (August 14, 2002).
Does it rain a lot in Boston in August?
About 9 days in August have at least 0.01 in of precipitation, and the normal total is 3.2 in. The wettest August in 1991-2020 was in 2011 (7.7 in); the driest was in 2007 (0.7 in).
Is August a good time to visit Boston?
August ranks 4th of 12 months on our comfort score for Boston (60 out of 100). It has about 8 comfortable days and about 4 days at 90°F or hotter. The best months are May, June and September.
Where the numbers come from
- Temperature, rain, snowfall, frost dates, humidity and wind by hour and cloud cover: Boston Logan Intl Airport (USW00014739), 2.5 mi E of the city center, 12 ft . NOAA normals and daily records, 1991-2020.
- Snow depth: Hingham (USC00193624), 12 mi SE of the city center, 35 ft . NOAA normals and daily records, 1991-2020.
- Daily humidity and wind: Gen E L Logan International Airport (725090-14739), 2.5 mi E of the city center, 11 ft . Hourly observations, 1991-2020.