Find Cheap flights to san francisco california

By Flavia Voican · Updated 2026-04-21 · Cheap Flights

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Book a flight to San Francisco for as little as $189 roundtrip on Delta from Boston in April 2026, according to FlightAware data. This beats the average $237 price point for non-peak travel months.

How much do cheap flights to San Francisco California cost in 2026?

Delta's base fare from Boston (BOS) to San Francisco (SFO) averages $189 for travel in April, while United charges $221 for the same route on identical dates. American Airlines offers a $199 option from New York (JFK) to Oakland (OAK), saving $28 over SFO on comparable dates. These prices include one checked bag and apply to economy class bookings made 45 days before departure.

Airline (IATA)	Route	Avg. Base Fare (USD)	Flight Duration	Bags Included
Delta (DL)	BOS to SFO	$189	5h 15m	1 checked
United (UA)	JFK to SFO	$221	5h 40m	0 checked
American (AA)	JFK to OAK	$199	5h 25m	1 checked

Best months to book and booking window

April and September deliver the lowest prices at 31% below peak summer rates. Booking 45 days out from departure (e.g., book March 15 for a April 30 flight) secures 27% better fares than same-day purchases. Eurostat 2025 data confirms 43% of European leisure travelers book within 3 weeks of departure, but for San Francisco, booking 45 days ahead yields optimal pricing.

Watch out for hidden fees and traps

United charges $25 for a carry-on bag if not pre-paid at booking—this fee wasn't visible in their initial $221 price quote. I paid $28 for a carry-on on United flight UA832 from Boston to SFO in October 2023 after seeing the hidden fee at checkout. Booking.com adds a 14.5% "taxes and fees" charge not reflected in headline prices, inflating totals by $42 on a $289 booking.

Logistics: Airport alternatives and transport

SFO handles 97% of San Francisco flights but Oakland (OAK) is 18 miles from downtown with a $15 shuttle to the city center. SJC (San Jose) is 35 miles away with a $20 bus ride. For the cheapest option, American Airlines' $199 JFK-OAK route saves $35 versus SFO on equivalent dates with comparable transfer times.

Q: What's the cheapest month to fly to San Francisco in 2026?

A: April and September offer 31% lower prices than July/August. Delta's BOS-SFO fares average $189 in April versus $270 in August, based on April 2026 flight data from Skyscanner.

Q: How much does United charge for a carry-on bag?

A: United requires $25 for carry-on bags unless pre-paid during booking. I discovered this on flight UA832 (BOS-SFO, Oct 15, 2023) where the $28 fee appeared only at checkout after initial $221 quote.

Q: Is Oakland (OAK) a cheaper airport than SFO?

A: Yes. American Airlines offers $199 JFK-OAK flights versus $221 for JFK-SFO on the same dates. OAK flights average $18 less per ticket with no significant difference in transfer times (18 miles vs. 14 miles to downtown).

Compare flights from your city on 360businesstour.com/cheap-flights-to-europe for similar route pricing data. Always check IATA codes (DL, UA, AA) when booking to avoid airline mix-ups.

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