There are low fares $484 to $508 to London from all three Bay Area airports for early to mid-August departures with all three major airlines American, Delta and United.
American Airlines San Jose SJC – Charlotte CLT – New York JFK – London LGW – Tampa TPA – Phoenix PHX – San Jose SJC
Nonstop flights to London price in low $700s.
Delta Airlines (Virgin Atlantic) San Jose SJC – Las Vegas LAS – London LGW – Las Vegas LAS – San Jose SJC
United Airlines San Francisco SFO – Houston IAH – London LHR – Munich MUC – San Francisco SFO
American Airlines Oakland OAK – Phoenix PHX – Tampa TPA – London LGW – Tampa TPA – Phoenix PHX – Oakland OAK