Belfast (ME) monthly weather averages

Average daytime temperature

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

Belfast average temperature chart (Celsius) Belfast average temperature chart (Fahrenheit)
Average monthly temperatures in Belfast (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C -2.3 -0.9 4.2 10.8 17.5 22.4 25.5 24.6 19.9 14 7.3 0.2
°F 27.9 30.5 39.5 51.4 63.5 72.4 78 76.3 67.9 57.1 45.1 32.3

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.

Belfast monthly rainfall chart (mm) Belfast monthly rainfall chart (inches)
Average monthly rainfall in Belfast (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 91 78 95 95 95 90 83 83 91 97 116 110
inches 3.6 3.1 3.7 3.7 3.7 3.6 3.3 3.3 3.6 3.8 4.6 4.3
Rainy days 12 10 12 12 12 12 11 11 10 11 13 13

Average annual rainfall in Belfast: 1100.734mm (433.4 inches)

Average daily sunshine

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

Belfast average daily sunshine chart
Average daily sunshine Belfast
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 4.3 5.2 5.9 6.6 7.6 8.2 8.5 8.2 7 5.7 4 3.7

Day / night temperatures

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

Belfast average minimum / maximum temperatures (Celsius) Belfast average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Belfast (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -12.8 -11.4 -5.4 0.6 6.2 11.3 14.6 13.9 9.2 3.8 -1.1 -9.2
Max °C -2.1 -0.6 4.4 11 17.8 22.7 25.8 24.9 20.2 14.2 7.5 0.4
Min °F 9.1 11.5 22.3 33.1 43.2 52.3 58.3 57 48.6 38.8 30 15.4
Max °F 18.7 21.2 31.1 42.4 53.6 62.6 68.4 66.9 58.5 48.2 37.8 24.1

Sea temperature

The graph below shows the average sea temperature.

Belfast average sea temperature chart (Celsius) Belfast average sea temperature chart (Fahrenheit)
Average sea temperature around Belfast in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 5.4 4.1 3.6 4.8 7.8 11.5 14.8 15.8 14.1 11.5 9.2 7.2
°F 41.8 39.3 38.5 40.7 46.1 52.8 58.7 60.5 57.4 52.7 48.5 45

Wind speed

The graph below shows the average wind speed.

Belfast average winspeed by month (km/h) Belfast average winspeed by month (mph)
Average wind speed in Belfast (mph and kmh)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
km/h 16 16 17 17 15 14 12 12 13 14 15 15
mph 10 10 11 10 9 9 8 7 8 9 9 9

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.

Belfast relative humidity averages
Average relative humidity in Belfast
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
70% 69% 69% 70% 71% 75% 77% 78% 79% 77% 77% 74%