Route reliability record
EWR→SFO
Newark to San Francisco
- Flights
- 4,349
- Period
- September 2025 to August 2026
- Distance
- 2,565 mi
- Carriers
- 2
This route draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is an hour and a half behind schedule. Build slack into anything you connect to. That rests on 4,349 EWR to SFO flights, of which Alaska Airlines flew 486 at 77.3% on time.
Best time to fly EWR to SFO: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 76.9% of the time and Tuesday flights 75.6%, against 67.9% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 9 points behind the country as a whole. Across a thousand flights that is about 94 extra late arrivals.
Key figures
On time
67.9%
Arrivals under 15 minutes late, of 4,241 completed flights
Avg delay
88 min
Across delayed arrivals only, not all flights
Cancelled
2.30%
National rate is 1.89%
Best carrier
Alaska
77.3% on time across 486 flights
These figures cover 4,349 flights between September 2025 and August 2026. Beyond the headline rate, 14.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Which airline is most reliable on EWR to SFO
The choice of carrier is not cosmetic here. Alaska Airlines arrives on time 77.3% of the time; United Airlines manages 66.7%. Sample sizes sit next to every figure, because a two-point gap across 3,863 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 486 | 77.3% | 63 min | 1.23% | B |
| United Airlines | 3,863 | 66.7% | 90 min | 2.43% | C |
Alaska leads United by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Flight by flight
Flights on EWR to SFO
The flight numbers below flew this route at least 250 times in the period, busiest first. Each has its own record, with its schedule and delay causes.
- United 177708:4572.5% · 365 flights
- United 64810:0070.9% · 365 flights
- United 232815:0065.4% · 365 flights
- United 134312:0064.1% · 363 flights
- United 211506:0083.2% · 362 flights
- United 122714:0069.3% · 341 flights
- United 196007:0070.8% · 339 flights
- United 134017:0060.4% · 338 flights
- United 184418:0060.7% · 326 flights
- United 155819:2049.8% · 267 flights
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Best ways to make this trip
The most reliable ways to fly Newark to San Francisco
Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. EWR → SFONewark to San Francisco | Alaska Airlines | 76.3% | 77.3% | 1.23% | 8am–11am, Wed | — |
| 2. JFK → SFONew York to San Francisco | American Airlines | 72.5% | 74.6% | 2.86% | 5am–8am, Tue | AA 76 06:00 |
| 3. JFK → SFONew York to San Francisco | JetBlue Airways | 71.3% | 73.4% | 2.86% | 5am–8am, Tue | B6 15 08:00 |
| 4. JFK → SFONew York to San Francisco | Alaska Airlines | 70.0% | 71.7% | 2.43% | 11am–2pm, Sat | AS 227 09:30 |
| 5. JFK → SFONew York to San Francisco | Delta Air Lines | 65.8% | 67.3% | 2.20% | 8am–11am, Tue | DL 679 14:55 |
Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 11 points between the best and worst carrier.
- 5am–8am841 flights76.9%
- 8am–11am933 flights71.7%
- 11am–2pm577 flights65.5%
- 2pm–5pm859 flights68.2%
- 5pm–8pm918 flights58.9%
- 8pm–5am221 flights59.6%
Scale runs 50% to 80%.
The 5pm–8pm window is where this operation falls apart: 58.9% on time, against 76.9% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 933 flights scheduled in it.
Explore
Filter EWR to SFO by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On EWR to SFO, the best departure window is 5am–8am at 76.9% on time and the worst is 5pm–8pm at 58.9%, a wide gap of 18.0 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am76.9%
- 8–11am71.7%
- 11am–2pm65.5%
- 2–5pm68.2%
- 5–8pm58.9%
- 8pm–5am59.6%
best all US flightsScale 50% to 95%.
Across the year
When delays peak on this route
This route's year swings by 30 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
June is the worst month at 51.5% on time, 30 points below March, the best at 81.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. May was the busiest month here, with 404 flights.
Across the week, Tuesday is the strongest day at 75.6% on time and Sunday the weakest at 63.2%, a spread of 12 points.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 120,000 reported delay minutes.
- 36%Carrier
- 32%National Airspace System
- 28%Late-arriving aircraft
- 4%Extreme weather
- 0%Security
The largest share of delay minutes, 36%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 43,000 of the 120,000 delay minutes reported here. The split is drawn from 120,278 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 76.9% on time here.
Cancellations sit at 2.30% against a national 1.89%, which is ordinary. Diversions add another 0.18%.
Connections and stage length
What a delay here actually costs
14.1% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
At 2,565 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg is a different operation and performs like one: it runs 76.8% on time across 4,348 flights, 9 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 9 points of difference.
The sample behind these figures is 4,349 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
Work out the risk of missing a connection in SFO after this flight
What to do with this
Booking this route
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 81.2% on time and June 51.5%, a swing of 30 points. If the dates move at all, move them out of June before you think about anything else. 4,241 completed flights over 12 months sit behind that.
Common questions
EWR to SFO questions
How often is EWR to SFO delayed?
About one flight in three arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 32.1% of the 4,349 flights in this analysis, against 22.7% nationally. Delayed flights are late by an hour and a half on average.
Which airline is most reliable on EWR to SFO?
Alaska Airlines leads at 77.3% on time across 486 flights. United Airlines is at the other end on 66.7%, a gap of 11 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.
What time of day has the fewest delays on EWR to SFO?
The 5am–8am departure window is the strongest at 76.9% on time. The 5pm–8pm window is the weakest at 58.9%, 18 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are June delays on EWR to SFO?
June is the weakest month at 51.5% on time, compared with 81.2% in March. Across the year that is 30 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- SFO to EWR — the return legseparate record
- Newark Liberty International (EWR) delay statistics
- San Francisco International (SFO) delay statistics
- Alaska Airlines on EWR to SFO77.3%
- United Airlines on EWR to SFO66.7%
- EWR to MCO, a related route77.9%
- LAX to SFO, a related route60.1%
- EWR to ATL, a related route76.9%
- Alaska Airlines on-time record77.3%
- United Airlines on-time record66.7%
- Same route, different airline: where the carrier you pick matters most
- How often a connection fails at the major US hubs
Direction matters. EWR to SFO and SFO to EWR are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
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Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.