Summer Begins?

 
At 4:28 Monday morning the sun reached its northern most point above the earth, the Tropic of Cancer at 23.5° north latitude.  This marked the beginning of astronomical summer. 

The Bay Area sits at 37° degrees north latitude.  The sun's highest angle from the horizon reaches 75.7° during the Summer Solstice. 

Meteorological summer is June, July and August.  These are the three warmest months across the majority of our country. 

If we think in, let's say, logical terms, summer would be the three warmest months.  What you'll find below is the three hottest months for each Bay Area city.  Interesting how so few fall in the three month June, July, August time period.   

June - July - August
Cloverdale
Martinez
Redwood City

July - August - September
Angwin
Antioch
Berkeley
Calistoga
Fremont
Gilroy
Graton
Healdsburg
Kentfield
Los Gatos
Markley Cove
Mount Diablo
Mount Hamilton
Napa
Newark
Oakland
Palo Alto
Petaluma
St. Helena
San Jose
San Rafael
Santa Rosa
Sonoma
Walnut Creek

August - September - October
Oceanside
Richmond
San Francisco
SFO