Saint Helens (OR) monthly weather averages

Average daytime temperature

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

Saint Helens average temperature chart (Celsius) Saint Helens average temperature chart (Fahrenheit)
Average monthly temperatures in Saint Helens (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 6.8 9.3 11.8 14.3 17.9 21.2 24.1 24.4 21.7 16.3 10.3 6.8
°F 44.2 48.8 53.3 57.8 64.2 70.2 75.3 75.9 71 61.3 50.5 44.2

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.

Saint Helens monthly rainfall chart (mm) Saint Helens monthly rainfall chart (inches)
Average monthly rainfall in Saint Helens (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 191 138 125 89 64 52 22 33 55 105 182 202
inches 7.5 5.4 4.9 3.5 2.5 2 0.9 1.3 2.2 4.1 7.2 8
Rainy days 18 16 17 15 12 9 5 6 8 12 19 19

Average annual rainfall in Saint Helens: 1180.767mm (464.9 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in Saint Helens

Saint Helens average daily sunshine chart
Average daily sunshine Saint Helens
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 3 4.5 6.5 7.7 9.2 10.1 11.2 10.1 8.3 5.3 2.9 2.3

Day / night temperatures

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

Saint Helens average minimum / maximum temperatures (Celsius) Saint Helens average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Saint Helens (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C -0.2 0.9 2 3.4 6.1 8.9 10.6 10.5 8.2 4.9 2.6 0.5
Max °C 7 9.6 12.1 14.6 18.2 21.5 24.4 24.7 22 16.6 10.5 7
Min °F 31.7 33.5 35.5 38.1 42.9 48 51.1 50.9 46.8 40.7 36.6 32.8
Max °F 38.1 41.4 44.6 48.2 53.8 59.4 63.5 63.7 59.2 51.3 43.7 38.7

Sea temperature

The graph below shows the average sea temperature.

Saint Helens average sea temperature chart (Celsius) Saint Helens average sea temperature chart (Fahrenheit)
Average sea temperature around Saint Helens in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 9.1 9 9.1 9.5 10.4 11.7 12.9 13.5 13.3 12 10.7 9.6
°F 48.3 48.1 48.4 49.1 50.7 53.1 55.3 56.3 55.9 53.6 51.2 49.2

Wind speed

The graph below shows the average wind speed.

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

Saint Helens relative humidity averages
Average relative humidity in Saint Helens
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
82% 79% 76% 73% 70% 68% 65% 67% 71% 79% 83% 84%