San Francisco (SFO) mixes domestic Terminals 1–3 with International Terminal A and G. United’s Polaris Lounge in International G is the premium benchmark for transpacific business; BART reaches downtown in about thirty minutes. Pad international arrival formalities and fog-season irregular operations as of July 2026.
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How is San Francisco SFO laid out and which terminal should you use?
Domestic flights use Terminals 1–3. International arrivals and many long-haul departures use International Terminal A and G. United anchors a large share of transpacific and domestic connecting traffic — follow the boarding-pass terminal closely.
This SFO guide covers terminals, connections, layovers, BART, lounges and delay tips for July 2026.
Compare LAX and JFK for US gateways. See San Francisco and British Airways for UK non-stops.
Figures are illustrative planning bands as of July 2026.
| Terminal | Typical posture | Note |
|---|---|---|
| T1–T3 | Domestic | Renovated piers <!-- VERIFY --> |
| International A / G | Long-haul arrivals & departures | Polaris in G |
| United | Largest connecting carrier | Domestic + transpacific |
| BART | To downtown SF | ~30 min band |
| vs LAX | Often easier city rail | Compare fares |
What connection time should you plan at San Francisco International Airport (SFO)?
Protected United and partner connections can work near published minima on calm days. International-to-domestic turns need wider buffers for immigration and re-security. Fog and ATC programmes can erase tight MCT.
Through-checked bags on a single ticket are the calm path. Prefer protected metal when shopping flight deals.
See flight delay compensation rights for qualifying UK/EU origin coupons.
| Transfer shape | Planning band | Why it matters |
|---|---|---|
| Domestic ↔ domestic through-ticket | Often ~1–1.5 hrs comfort | Airside when same ticket <!-- VERIFY --> |
| Intl → domestic through-ticket | Often ~2.5–3.5 hrs comfort | Immigration + re-security |
| Self-transfer with bags | Often 4+ hrs preferred | Full reclaim + re-check |
| Fog / marine layer days | Add contingency | SFO irregular ops |
| Late-night sparse banks | Avoid tight turns | Fewer recovery options |
What can you do on a 3, 6 or 12-hour layover at SFO?
Short layovers stay airside with Polaris or Centurion access if eligible. Six hours suits lounge rest. Twelve hours can justify BART into downtown only when entry is complete and return security time is honest.
Three hours after an international landing are often formalities-heavy.
Twelve-hour windows open a short Embarcadero visit. See San Francisco.
| Layover length | Realistic options | Exit note |
|---|---|---|
| ~3 hours | Stay airside; lounge if eligible | City exit tight after intl |
| ~6 hours | Polaris / Centurion rest | City only with surplus <!-- VERIFY --> |
| ~12 hours | BART downtown half-day | Pad return security |
| Overnight | Airport hotel or lounge | Book peak banks early |
| Sleep / showers | Polaris; Centurion; hotel | Eligibility follows cabin/card |
What is the fastest way from SFO to downtown San Francisco?
BART from the airport station usually reaches downtown in about thirty minutes when service is normal. Ride-hailing trades predictability for door-to-door drops across the peninsula.
Follow BART signs from arrivals; buy tickets or use contactless where accepted.
See San Francisco for neighbourhood planning.
| Mode | Typical time | Typical fare band | Best when |
|---|---|---|---|
| BART | ~30 min downtown | BART fare <!-- VERIFY --> | Downtown; daytime |
| Ride-hail / taxi | ~25–45 min traffic | Surge / meter | Heavy bags; late night |
| Hotel car | Pre-booked | Quoted | Families |
| SamTrans / bus | Longer than BART | Cheaper | Budget |
| Hire car | 101 / 280 dependent | Rental + parking | Beyond the city |
Which lounges can you use at SFO?
United Polaris Lounge in International Terminal G is the premium benchmark for eligible Polaris and Star Alliance Gold international departures. Centurion Lounge in Terminal 3 serves cardholders. Confirm access rules before you walk.
Polaris access is stricter than standard United Clubs.
Priority Pass exclusions are common at SFO — check the live list.
| Lounge | Typical access | Note |
|---|---|---|
| United Polaris | Polaris / Star Gold intl | Int’l G <!-- VERIFY --> |
| United Club | Membership / cabin | Multiple terminals |
| Centurion Lounge | Amex Centurion rules | Terminal 3 |
| Priority Pass | Membership + exclusions | Confirm live list |
| Pay-in day pass | Where offered | Peak slots fill |
Does SFO have free Wi-Fi and left-luggage storage?
SFO typically offers free Wi-Fi after a splash-page or SMS login for messaging and light browsing. Left-luggage desks operate landside with per-bag daily rates when open.
Use the official airport network; carry an eSIM for reliable uploads on long layovers.
Photograph bag tags; never store passports or medication in left luggage.
| Service | Planning note | Tip |
|---|---|---|
| Free Wi-Fi | Splash or SMS login common | Official SFO SSID <!-- VERIFY --> |
| Paid upgrade | Faster sessions on busy days | Only if needed |
| Left luggage | Per bag / per day | Landside; check hours <!-- VERIFY --> |
| Luggage wrap | Optional desks | Airlines may open bags |
| Trolleys / porters | Landside assistance | Useful on long walks |
What should you do if your SFO flight is delayed or cancelled?
Use the operating-carrier app first for rebooking, keep boarding passes and delay timestamps, and ask about hotels when overnight disruption is covered. UK/EU compensation frameworks can still attach to qualifying origin coupons even when you are standing at SFO.
Start with flight delay compensation rights for the legal map, then file through your carrier with evidence.
Separate tickets weaken onward protection — prefer single tickets when shopping flight deals.
- Screenshot delay notices and new flight offers in the airline app
- Ask for meal or hotel care when rules require it on overnight misses
- Keep boarding passes and bag tags from the disrupted segment
- Note actual arrival time at the final destination for compensation thresholds
- Do not leave for the city until your new departure is confirmed
What is the practical bottom line for using SFO well?
Pad fog-season connections, use BART for downtown hotels, and treat Polaris access as a cabin-and-status privilege rather than a walk-up given.
SFO rewards protected United tickets. Pair with LAX, JFK and San Francisco.
[CTA: kiwi | Compare San Francisco SFO one-stops] · [CTA: aviasales | Watch SFO prices on flexible dates]
Frequently asked questions
- Where is the United Polaris Lounge at SFO?
- International Terminal G near the G gates — confirm access rules. <!-- VERIFY -->
- How long is BART from SFO to downtown?
- About thirty minutes when service is normal. <!-- VERIFY -->
- SFO or LAX for California?
- SFO often has easier rail into the city; compare fares and final addresses.
- Does fog delay SFO flights?
- Marine layer and fog programmes can disrupt banks — pad connections in summer mornings.
- Which terminal for international arrivals?
- International Terminal A and G — follow your boarding pass.
- Is there a Centurion Lounge at SFO?
- Yes in Terminal 3 for eligible Amex cardholders. <!-- VERIFY -->