The hottest days of summer across most of the United States happen, onaverage, during the third and fourth weeks of July.It is at this time that normal temperature "catches up," or comes intoequilibrium with, the input of solar energy, which peaks with the SummerSolstice in June. This culminates the six-month-long warming that begins at thedepths of winter, usually in January.
An exception to the late-July topping of normal temperature is to be foundalong the West Coast. Here, cooling sea breezes are normally strong throughmidsummer then slacken later as heating weakens inland.
In San Francisco, normal mean temperature is highest during early tomid-September. August, on average, is warmest in Los Angeles and San Diego.
Story by AccuWeather.com Senior Meteorologist Jim Andrews.
