Route reliability record
SFO→MIA
San Francisco to Miami
- Flights
- 1,741
- Period
- September 2025 to August 2026
- Distance
- 2,585 mi
- Carriers
- 2
This route lands a B+, about a point worse than the national rate of 77.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 1,741 SFO to MIA flights, of which United Airlines flew 604 at 77.9% on time.
Best time to fly SFO to MIA: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 89.0% of the time and Wednesday flights 81.4%, against 76.5% for the route overall.
The US average over the same twelve months is 77.3%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
76.5%
Arrivals under 15 minutes late, of 1,726 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.57%
National rate is 1.89%
Best carrier
United
77.9% on time across 604 flights
These figures cover 1,741 flights between September 2025 and August 2026. The median arrival is 5 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Carrier by carrier
Which airline is most reliable on SFO to MIA
The two carriers here are closely matched: 2 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 | 604 | 77.9% | 39 min | 0.00% | B+ |
| American Airlines | 1,137 | 75.8% | 79 min | 0.88% | B+ |
No carrier stands out. United tops the table at 77.9%, 2 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 San Francisco to Miami
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. SFO → FLLSan Francisco to Fort Lauderdale | United Airlines | 83.5% | 83.5% | 0.00% | 8am–11am, Thu | — |
| 2. SFO → MIASan Francisco to Miami | United Airlines | 77.9% | 77.9% | 0.00% | 8pm–5am, Tue | — |
| 3. SFO → FLLSan Francisco to Fort Lauderdale | JetBlue Airways | 76.4% | 76.5% | 0.13% | 5am–8am, Wed | B6 378 23:59 |
| 4. SFO → MIASan Francisco to Miami | American Airlines | 75.1% | 75.8% | 0.88% | 5am–8am, Wed | — |
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 19 points, against 2 points between the best and worst carrier.
- 5am–8am248 flights89.0%
- 8am–11am428 flights73.5%
- 11am–2pm371 flights69.8%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am694 flights77.5%
Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.
The weak window here is the middle of the day, not the evening: 11am–2pm runs 69.8% on time against 89.0% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 8pm–5am window is the busiest, with 694 flights scheduled in it.
Explore
Filter SFO to MIA 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 SFO to MIA, the best departure window is 5am–8am at 89.0% on time and the worst is 11am–2pm at 69.8%, a wide gap of 19.2 points. All US flights leaving 5am–8am ran 89.3%.
- 5–8am89.0%
- 8–11am73.5%
- 11am–2pm69.8%
- 2–5pm—
- 5–8pm—
- 8pm–5am77.5%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 26 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 62.5% on time, 26 points below October, the best at 88.6%. 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, Wednesday is the strongest day at 81.4% on time and Thursday the weakest at 73.9%, a spread of 8 points.
Delay causes
Why this route gets delayed
Carrier accounts for 47% of the 27,000 delay minutes carriers reported here, and the remaining four split what is left.
- 47%Carrier
- 31%Late-arriving aircraft
- 21%National Airspace System
- 1%Extreme weather
- 0%Security
The largest share of delay minutes, 47%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 13,000 of the 27,000 delay minutes reported here. The split is drawn from 26,654 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 89.0% on time here.
Cancellations are rare at 0.57%, 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
5.9% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
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 70.7% on time across 1,740 flights, 6 points below 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 1,741 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 MIA 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. October runs 88.6% on time and July 62.5%, a swing of 26 points. If the dates move at all, move them out of July before you think about anything else. 1,726 completed flights over 12 months sit behind that.
Common questions
SFO to MIA questions
How often is SFO to MIA delayed?
About one flight in four arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 23.5% of the 1,741 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on SFO to MIA?
United Airlines leads at 77.9% on time across 604 flights. American Airlines is at the other end on 75.8%, a gap of 2 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 SFO to MIA?
The 5am–8am departure window is the strongest at 89.0% on time. The 11am–2pm window is the weakest at 69.8%, 19 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 SFO to MIA?
July is the weakest month at 62.5% on time, compared with 88.6% in October. Across the year that is 26 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
- MIA to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Miami International (MIA) delay statistics
- United Airlines on SFO to MIA77.9%
- American Airlines on SFO to MIA75.8%
- SFO to LAX, a related route70.9%
- ATL to MIA, a related route71.2%
- SFO to SEA, a related route72.3%
- United Airlines on-time record77.9%
- American Airlines on-time record75.8%
- The best time of day to fly, according to 7.05 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SFO to MIA and MIA to SFO 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.