Boston climate

Boston Weather in August

NASA POWER reanalysis for the half-degree grid cell around Boston, 1991-2020; a grid cell is an area average and can differ from a thermometer in town by several degrees

Average highs run from 22°C on August 1 to 20°C on August 31, and lows from 13°C to 12°C. Normal precipitation for the month is 65 mm over about 12 wet days.

August day by day

The normal high and low for each date, in °C.

Normal daily high and low temperature at Boston, in °C, with the record for each date.5101520253035151015202530
  • Normal low
  • Normal high
  • Reanalysis extreme high
  • Reanalysis extreme low

August at a glance

Average high
21°C
Average low
13°C
Precipitation
65 mm
Reanalysis high
31°CAug 10, 2003
Reanalysis low
7°CAug 24, 2014
Daylight
15 h 36 min to 13 h 43 min
Cloud cover
73%
Humidity
80%
Dew point
13°C
Wind
16.9 km/h

Every day of the month

A wet day has at least 1 mm of precipitation in the reanalysis.

DateNormal highNormal lowReanalysis highReanalysis lowChance wet
Aug 122°C13°C28°C 201310°C 201639%
Aug 222°C13°C27°C 199910°C 199640%
Aug 322°C13°C27°C 201810°C 199641%
Aug 422°C13°C25°C 200310°C 202040%
Aug 522°C13°C26°C 201810°C 201740%
Aug 622°C13°C29°C 20039°C 201740%
Aug 722°C13°C29°C 202010°C 201238%
Aug 822°C13°C27°C 19979°C 200737%
Aug 921°C13°C28°C 20039°C 201638%
Aug 1021°C13°C31°C 200310°C 199339%
Aug 1121°C13°C28°C 19979°C 200140%
Aug 1221°C13°C27°C 202010°C 199341%
Aug 1321°C13°C25°C 19977°C 199341%
Aug 1421°C13°C24°C 20029°C 199441%
Aug 1521°C13°C28°C 20018°C 199442%
Aug 1621°C13°C26°C 19978°C 199944%
Aug 1721°C13°C27°C 20029°C 199944%
Aug 1821°C13°C27°C 201210°C 199145%
Aug 1921°C13°C27°C 19969°C 199146%
Aug 2021°C13°C27°C 19977°C 201445%
Aug 2121°C12°C25°C 19918°C 201444%
Aug 2221°C12°C27°C 20158°C 199944%
Aug 2321°C12°C26°C 20168°C 201444%
Aug 2420°C12°C26°C 20197°C 201443%
Aug 2520°C12°C28°C 20198°C 199342%
Aug 2620°C12°C28°C 20199°C 199841%
Aug 2720°C12°C29°C 20198°C 199841%
Aug 2820°C12°C24°C 20179°C 199840%
Aug 2920°C12°C24°C 20089°C 200040%
Aug 3020°C12°C24°C 20059°C 199440%
Aug 3120°C12°C27°C 20058°C 201238%

Chance of rain

The chance of at least 1 mm of precipitation in the reanalysis on each date at Boston, in percent.010203040501102030
  • Chance of a wet day

Sunrise and sunset

Times for 2026, local time (GMT+1).

August 1
sunrise 5:18 AM, sunset 8:54 PM
August 31
sunrise 6:08 AM, sunset 7:51 PM

Every day of August: sun and moon

Other months

Sources

Cloud, humidity, wind and sunshine, and temperature and precipitation: NASA POWER (MERRA-2, CERES and GEWEX SRB), 1991-2020. The data was obtained from the National Aeronautics and Space Administration (NASA) Langley Research Center's Prediction Of Worldwide Energy Resources (POWER) project funded through the NASA Earth Science Division: POWER Daily API v2, accessed 2026-09-24. Sun and moon: computed with the NOAA solar equations and Meeus.