Such seas result in good surfing conditions at many of the beaches along the coast.  Water temperatures in the 50’s in the San Francisco area, however, discourage all but the most hardy.  Water temperatures in the 60’s during much of the year on the southern California beaches makes the sport more enjoyable there.

RELATIVE HUMIDITY – In general, relative humidities are moderate to high along the coast throughout the year.  Inland hunidities are high during the winter and low during the summer.  Since the ocean is the source of the cool, humid, maritime air of summer, it follows that with increasing distance from the ocean, relative humidity tends to decrease. Where mountain barriers prevent the free flow of marine air inland, humidities decrease rapidly.  Where openings in these barriers permit a significant influx of cool, moist air it mixes with the drier inland air, resulting in a more gradual decrease of moisture.  This pattern is characteristic of most coastal valleys.

The Mojave and Colorado Deserts experience very low humidities with the high temperatures of summer.  Winter readings are usually moderate to low and only occasionally do moist air and cool temperatures combine to produce high relative humidity readings.