Route reliability record
SFO→MIA
San Francisco to Miami
- Flights
- 1,725
- Period
- July 2025 to June 2026
- Distance
- 2,585 mi
- Carriers
- 2
This route lands a B+, level with the national rate of 77.6%. Roughly one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,725 SFO to MIA flights, of which American Airlines flew 1,102 at 77.8% on time.
Best time to fly SFO to MIA: a 5am–8am departure, ideally on a Wednesday. Flights in that window arrived on time 91.3% of the time and Wednesday flights 79.0%, against 77.4% for the route overall.
The US average over the same twelve months is 77.6%, 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
77.4%
Arrivals under 15 minutes late, of 1,710 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
0.58%
National rate is 1.81%
Best carrier
American
77.8% on time across 1,102 flights
These figures cover 1,725 flights between July 2025 and June 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.
Carrier by carrier
Which airline is most reliable on SFO to MIA
The two carriers here are closely matched: about a point 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 |
|---|---|---|---|---|---|
| American Airlines | 1,102 | 77.8% | 82 min | 0.91% | B+ |
| United Airlines | 623 | 76.8% | 39 min | 0.00% | B+ |
No carrier stands out. American tops the table at 77.8%, about a point clear of the bottom, which is inside the range this kind of sample moves year to year.
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 | 85.5% | 85.9% | 0.41% | 8am–11am, Tue | — |
| 2. SFO → FLLSan Francisco to Fort Lauderdale | JetBlue Airways | 77.9% | 78.2% | 0.39% | 5am–8am, Fri | B6 378 23:59 |
| 3. SFO → MIASan Francisco to Miami | American Airlines | 77.1% | 77.8% | 0.91% | 5am–8am, Wed | — |
| 4. SFO → MIASan Francisco to Miami | United Airlines | 76.8% | 76.8% | 0.00% | 8pm–5am, Thu | — |
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 20 points, against about a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am186 flights91.3%
- 8am–11am484 flights75.1%
- 11am–2pm377 flights71.4%
- 2pm–5pm—
- 5pm–8pm—
- 8pm–5am678 flights78.6%
Scale runs 65% 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 71.4% on time against 91.3% 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 678 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 21 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.
August is the worst month at 68.1% on time, 21 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. June was the busiest month here, with 174 flights.
The day of the week is close to irrelevant here: 4 points separates the best day from the worst. Weekly demand peaks are not what drives the delays on this operation.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 46% of the 26,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 46%Carrier
- 31%Late-arriving aircraft
- 22%National Airspace System
- 1%Extreme weather
- 0%Security
The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 12,000 of the 26,000 delay minutes reported here. The split is drawn from 25,571 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 91.3% on time here.
Cancellations are rare at 0.58%, below the national 1.81% 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
5.3% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says 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 71.6% on time across 1,725 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 1,725 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 August 68.1%, a swing of 21 points. If the dates move at all, move them out of August before you think about anything else. 1,710 completed flights over 12 months sit behind that.
Common questions
SFO to MIA questions
How often is SFO to MIA delayed?
Roughly 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 22.6% of the 1,725 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
Which airline is most reliable on SFO to MIA?
American Airlines leads at 77.8% on time across 1,102 flights. United Airlines is at the other end on 76.8%, a gap of about a point. 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 91.3% on time. The 11am–2pm window is the weakest at 71.4%, 20 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 August delays on SFO to MIA?
August is the weakest month at 68.1% on time, compared with 88.6% in October. Across the year that is 21 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
- American Airlines on SFO to MIA77.8%
- United Airlines on SFO to MIA76.8%
- SFO to LAX, a related route73.9%
- ATL to MIA, a related route71.0%
- SFO to SEA, a related route73.7%
- American Airlines on-time record77.8%
- United Airlines on-time record76.8%
- The best time of day to fly, according to 7.04 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, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.