Route reliability record
MIA→SFO
Miami to San Francisco
- Flights
- 1,740
- Period
- September 2025 to August 2026
- Distance
- 2,585 mi
- Carriers
- 2
This route sits in the middle of the pack with a C+. About seven flights in ten arrive on time by the DOT's definition, 7 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 1,740 MIA to SFO flights, of which United Airlines flew 603 at 73.7% on time.
Best time to fly MIA to SFO: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 90.4% of the time and Tuesday flights 83.0%, against 70.7% for the route overall.
The national on-time rate over the same period is 77.3%, so this route runs 7 points behind the country as a whole. Across a thousand flights that is about 66 extra late arrivals.
Key figures
On time
70.7%
Arrivals under 15 minutes late, of 1,725 completed flights
Avg delay
68 min
Across delayed arrivals only, not all flights
Cancelled
0.63%
National rate is 1.89%
Best carrier
United
73.7% on time across 603 flights
These figures cover 1,740 flights between September 2025 and August 2026. Beyond the headline rate, 10.8% 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 MIA to SFO
The two carriers here are closely matched: 5 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 603 | 73.7% | 74 min | 0.17% | C+ |
| American Airlines | 1,137 | 69.2% | 65 min | 0.88% | C+ |
No carrier stands out. United tops the table at 73.7%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
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Best ways to make this trip
The most reliable ways to fly Miami 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. 2 of the top 4 use a different airport at one end.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. FLL → SFOFort Lauderdale to San Francisco | United Airlines | 84.2% | 84.2% | 0.00% | 8am–11am, Thu | — |
| 2. FLL → SFOFort Lauderdale to San Francisco | JetBlue Airways | 75.0% | 75.2% | 0.27% | 5am–8am, Sat | B6 277 20:00 |
| 3. MIA → SFOMiami to San Francisco | United Airlines | 73.6% | 73.7% | 0.17% | 5am–8am, Tue | — |
| 4. MIA → SFOMiami to San Francisco | American Airlines | 68.6% | 69.2% | 0.88% | 5am–8am, Tue | — |
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 31 points, against 5 points between the best and worst carrier.
- 5am–8am345 flights90.4%
- 8am–11am291 flights85.5%
- 11am–2pm1 flights—
- 2pm–5pm53 flights71.7%
- 5pm–8pm831 flights59.4%
- 8pm–5am219 flights62.3%
Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 59.4% on time, against 90.4% 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 5pm–8pm window is the busiest, with 831 flights scheduled in it.
Explore
Filter MIA 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 MIA to SFO, the best departure window is 5am–8am at 90.4% on time and the worst is 5pm–8pm at 59.4%, a wide gap of 31.0 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am90.4%
- 8–11am85.5%
- 11am–2pm—
- 2–5pm71.7%
- 5–8pm59.4%
- 8pm–5am62.3%
best all US flightsScale 50% to 95%. Cells under 30 flights show a dash.
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.
July is the worst month at 55.7% on time, 30 points below March, the best at 86.1%. 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. July was the busiest month here, with 176 flights.
Across the week, Tuesday is the strongest day at 83.0% on time and Monday the weakest at 62.3%, a spread of 21 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 34,000 reported delay minutes.
- 37%National Airspace System
- 31%Late-arriving aircraft
- 28%Carrier
- 4%Extreme weather
- 0%Security
37% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 13,000 minutes out of 34,000, against a national NAS share of 21%. The split is drawn from 34,300 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 90.4% on time here.
Cancellations are rare at 0.63%, below the national 1.89% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.
Connections and stage length
What a delay here actually costs
10.8% 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 2,585 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 76.5% on time across 1,741 flights, 6 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 6 points of difference.
The sample behind these figures is 1,740 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 86.1% on time and July 55.7%, a swing of 30 points. If the dates move at all, move them out of July before you think about anything else. 1,725 completed flights over 12 months sit behind that.
Common questions
MIA to SFO questions
How often is MIA to SFO delayed?
Roughly 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 29.3% of the 1,740 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on MIA to SFO?
United Airlines leads at 73.7% on time across 603 flights. American Airlines is at the other end on 69.2%, a gap of 5 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 MIA to SFO?
The 5am–8am departure window is the strongest at 90.4% on time. The 5pm–8pm window is the weakest at 59.4%, 31 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 July delays on MIA to SFO?
July is the weakest month at 55.7% on time, compared with 86.1% 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 MIA — the return legseparate record
- Miami International (MIA) delay statistics
- San Francisco International (SFO) delay statistics
- United Airlines on MIA to SFO73.7%
- American Airlines on MIA to SFO69.2%
- MIA to ATL, a related route74.2%
- LAX to SFO, a related route60.1%
- MIA to LGA, a related route67.4%
- United Airlines on-time record73.7%
- American Airlines on-time record69.2%
- The best time of day to fly, according to 7.05 million flight records
- How often a connection fails at the major US hubs
Direction matters. MIA to SFO and SFO to MIA 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.