From most locations, the cheapest flights to San Francisco can be found during the month of March; however great deals can be found at other times.
In general, most flyers find the cheapest time to book a flight to San Francisco is about 51 days prior.
From most locations, the cheapest day to fly to San Francisco is Tuesday. Most users found that departing on a Friday was most expensive.
On average you can find the best deals on plane tickets to San Francisco when looking for flights with morning departure times.