San Marcos (CA) monthly weather averages

Average daytime temperature

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

San Marcos average temperature chart (Celsius) San Marcos average temperature chart (Fahrenheit)
Average monthly temperatures in San Marcos (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 17.7 18.5 18.6 20.4 22.5 25.2 28.1 28.7 27.3 24.6 20.7 18
°F 63.9 65.3 65.5 68.8 72.5 77.3 82.6 83.7 81.1 76.2 69.3 64.4

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.

San Marcos monthly rainfall chart (mm) San Marcos monthly rainfall chart (inches)
Average monthly rainfall in San Marcos (mm and inches)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
mm 73 63 64 29 10 2 1 4 8 9 45 53
inches 2.9 2.5 2.5 1.2 0.4 0.1 0.1 0.1 0.3 0.3 1.8 2.1
Rainy days 6 5 6 4 2 1 1 1 1 2 4 5

Average annual rainfall in San Marcos: 277.1mm (109.1 inches)

Average daily sunshine

The bar chart below shows the average daily sunshine hours in San Marcos

San Marcos average daily sunshine chart
Average daily sunshine San Marcos
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Hrs sunshine 8.4 8.8 9.3 10.3 9.4 9.7 11.3 10.9 9.6 8.9 8.4 8.2

Day / night temperatures

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

San Marcos average minimum / maximum temperatures (Celsius) San Marcos average minimum / maximum temperatures (Fahrenheit)
Maximum and minimum daily temperatures in San Marcos (degrees centigrade and fahrenheit)
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
Min °C 6 7 8 9.7 12.7 15 17.4 18.2 16.3 13 8.8 5.9
Max °C 18 18.8 18.9 20.7 22.8 25.4 28.4 29 27.6 24.9 21 18.3
Min °F 42.8 44.6 46.3 49.5 54.8 59 63.3 64.8 61.3 55.3 47.8 42.6
Max °F 53.6 55.2 56.1 59.4 63.9 68.4 73.2 74.5 71.4 66 58.8 53.8

Sea temperature

The graph below shows the average sea temperature.

San Marcos average sea temperature chart (Celsius) San Marcos average sea temperature chart (Fahrenheit)
Average sea temperature around San Marcos in degrees centigrade and fahrenheit
  Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
°C 14.9 14.9 15.1 15.6 16.6 18 19.8 20.5 20.4 19.3 17.5 15.7
°F 58.8 58.8 59.3 60 61.8 64.4 67.6 69 68.8 66.7 63.5 60.2

Wind speed

The graph below shows the average wind speed.

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

San Marcos relative humidity averages
Average relative humidity in San Marcos
Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec
62% 64% 64% 63% 66% 68% 69% 69% 69% 66% 64% 63%