Eureka (CA) monthly weather averages

Average daytime temperature

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

Eureka average temperature chart (Celsius) Eureka average temperature chart (Fahrenheit)
Average monthly temperatures in Eureka (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 11.8 12.7 13.1 13.9 15.4 17.3 18.7 19 18.6 16.6 14.1 11.9
°F 53.3 54.8 55.6 56.9 59.7 63.1 65.7 66.2 65.5 62 57.3 53.4

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.

Eureka monthly rainfall chart (mm) Eureka monthly rainfall chart (inches)
Average monthly rainfall in Eureka (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 201 162 165 86 40 14 4 14 26 86 206 206
inches 7.9 6.4 6.5 3.4 1.6 0.5 0.1 0.5 1 3.4 8.1 8.1
Rainy days 14 14 16 11 8 5 2 3 4 9 15 15

Average annual rainfall in Eureka: 1124.767mm (442.8 inches)

Average daily sunshine

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

Eureka average daily sunshine chart
Average daily sunshine Eureka
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 5 5.7 7.3 9.2 9.9 10.2 9.9 8.7 8.3 6.5 4.9 4.6

Day / night temperatures

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

Eureka average minimum / maximum temperatures (Celsius) Eureka average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in Eureka (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 4.2 5 5.3 5.8 7.6 9.6 10.7 11 10 8.2 6.4 4.6
Max °C 12 12.9 13.3 14.1 15.6 17.5 18.9 19.2 18.9 16.9 14.3 12.1
Min °F 39.6 40.9 41.5 42.4 45.7 49.2 51.3 51.8 49.9 46.7 43.4 40.2
Max °F 46.6 48 48.7 49.8 52.9 56.3 58.6 59.2 57.9 54.5 50.5 46.9

Sea temperature

The graph below shows the average sea temperature.

Eureka average sea temperature chart (Celsius) Eureka average sea temperature chart (Fahrenheit)
Average sea temperature around Eureka in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 11.4 11.2 11.2 11.2 11.7 12.4 13 13.7 13.9 13.3 12.8 12
°F 52.5 52.2 52.1 52.2 53.1 54.3 55.4 56.6 57 56 55 53.5

Wind speed

The graph below shows the average wind speed.

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

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.

Eureka relative humidity averages
Average relative humidity in Eureka
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
84% 80% 76% 72% 71% 67% 64% 65% 67% 74% 83% 85%