Boston (MA) monthly weather averages

Average daytime temperature

The bar chart below shows the average monthly peak daytime temperatures at Boston

Boston average temperature chart (Celsius) Boston average temperature chart (Fahrenheit)
Average monthly temperatures in Boston (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 1.2 2.4 7.3 13.4 19.4 24.5 27.6 26.4 22.3 16.7 10.5 3.7
°F 34.1 36.4 45.2 56 67 76.2 81.7 79.5 72.2 62.1 51 38.7

Please note: these are the average peak daytime temperatures (usually around mid-afternoon) so do not show daytime / night highs and lows. To see the daily range of temperatures have a look at the temperature max / min chart below.

Average rainfall & rainy days

The graph below shows the average rainfall and number of rainy days per month.

Boston monthly rainfall chart (mm) Boston monthly rainfall chart (inches)
Average monthly rainfall in Boston (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 93 93 97 93 85 80 75 85 82 87 111 105
inches 3.7 3.6 3.8 3.7 3.3 3.1 2.9 3.3 3.2 3.4 4.4 4.1
Rainy days 11 10 11 11 11 11 9 10 9 9 11 12

Average annual rainfall in Boston: 1056.834mm (416.1 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Boston

Boston average daily sunshine chart
Average daily sunshine Boston
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 5.8 6.4 7.2 7.9 8.9 9.9 10.2 9.4 8.3 7.1 5.2 5.1

Day / night temperatures

The graph below shows the daily range of temperatures for each month.

Boston average minimum / maximum temperatures (Celsius) Boston average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Boston (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -7.6 -6.7 -1.8 3.4 8.7 13.8 17.2 16.4 12 6.4 1.9 -4.6
Max °C 1.4 2.7 7.6 13.6 19.7 24.8 27.9 26.7 22.6 17 10.8 4
Min °F 18.3 20 28.9 38.1 47.7 56.8 62.9 61.4 53.6 43.5 35.3 23.8
Max °F 26.4 28.4 37.2 47.3 57.6 66.7 72.5 70.7 63.1 53.1 43.3 31.5

Sea temperature

The graph below shows the average sea temperature.

Boston average sea temperature chart (Celsius) Boston average sea temperature chart (Fahrenheit)
Average sea temperature around Boston in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 5.4 3.8 3.5 5.2 9.1 14 18.6 19.8 17.8 14.2 10.7 7.9
°F 41.8 38.8 38.3 41.4 48.4 57.3 65.4 67.7 64.1 57.6 51.3 46.2

Wind speed

The graph below shows the average wind speed.

Boston average winspeed by month (km/h) Boston average winspeed by month (mph)
Average wind speed in Boston (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 19 19 19 19 17 16 15 14 15 16 18 18
mph 12 12 12 12 11 10 9 9 9 10 11 11

A monthly average windspeed of over 16km/h or 10mph suggests a location is fairly windy.

Relative humidity

The graph below shows the average relative humidity.

Boston relative humidity averages
Average relative humidity in Boston
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
63% 63% 63% 62% 66% 69% 69% 72% 73% 70% 69% 66%