sentences:  Average annual precipitation is 480 mm (18.9 in), and the summer months are typically dry.Snowfall is rare, about once every 20 years, and is light and short-lived when it occurs.Summer months are characterized by coastal fog which arrives from the ocean around 10 p.m. and dissipates the next morning by 10 a.m. Winter months have many sunny and partly cloudy days, with frequent breaks between rainstorms.