Route reliability record
SFO→DTW
San Francisco to Detroit
- Flights
- 1,797
- Period
- July 2025 to June 2026
- Distance
- 2,079 mi
- Carriers
- 2
This route lands a B+, 2 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 55 minutes on average. That is a workable record, not a spotless one. That rests on 1,797 SFO to DTW flights, of which United Airlines flew 409 at 83.5% on time.
Best time to fly SFO to DTW: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 93.7% of the time and Tuesday flights 84.5%, against 79.4% 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
79.4%
Arrivals under 15 minutes late, of 1,779 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.83%
National rate is 1.81%
Best carrier
United
83.5% on time across 409 flights
These figures cover 1,797 flights between July 2025 and June 2026. The median arrival is 6 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 DTW
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 | 409 | 83.5% | 55 min | 0.73% | B+ |
| Delta Air Lines | 1,388 | 78.2% | 53 min | 0.86% | B+ |
No carrier stands out. United tops the table at 83.5%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.
Flight by flight
Flights on SFO to DTW
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.
Best ways to make this trip
The most reliable ways to fly San Francisco to Detroit
Every airline on this route, ranked by how often a scheduled flight actually operated and arrived on time, with its best departure time and most punctual flight number. No nearby airport pair beat these.
| Option | Airline | Success | On time | Cancelled | Best departure | Most punctual flight |
|---|---|---|---|---|---|---|
| 1. SFO → DTWSan Francisco to Detroit | United Airlines | 82.9% | 83.5% | 0.73% | 8am–11am, Sat | — |
| 2. SFO → DTWSan Francisco to Detroit | Delta Air Lines | 77.5% | 78.2% | 0.86% | 5am–8am, Tue | DL 772 05:50 |
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 23 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am365 flights93.7%
- 8am–11am151 flights89.4%
- 11am–2pm516 flights78.5%
- 2pm–5pm303 flights70.8%
- 5pm–8pm2 flights—
- 8pm–5am460 flights71.6%
Scale runs 60% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 93.7% of the time, against 70.8% for the afternoon window. That is 23 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 516 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.
June is the worst month at 68.0% on time, 21 points below April, the best at 89.0%. 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 190 flights.
Across the week, Tuesday is the strongest day at 84.5% on time and Sunday the weakest at 76.2%. 8 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 19,000 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.
- 52%Late-arriving aircraft
- 32%Carrier
- 16%National Airspace System
- 1%Extreme weather
52% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 19,000 reported delay minutes here, that single category outweighs weather by 52 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 19,462 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 93.7% on time here.
Cancellations are rare at 0.83%, 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
6.4% 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 roughly 55 minutes, which a normal layover absorbs.
At 2,079 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 67.7% on time across 1,799 flights, 12 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 12 points of difference.
The sample behind these figures is 1,797 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 DTW 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. April runs 89.0% on time and June 68.0%, a swing of 21 points. If the dates move at all, move them out of June before you think about anything else. 1,779 completed flights over 12 months sit behind that.
Common questions
SFO to DTW questions
How often is SFO to DTW delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 20.6% of the 1,797 flights in this analysis, against 22.4% nationally. Delayed flights are late by roughly 55 minutes on average.
Which airline is most reliable on SFO to DTW?
United Airlines leads at 83.5% on time across 409 flights. Delta Air Lines is at the other end on 78.2%, 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 SFO to DTW?
The 5am–8am departure window is the strongest at 93.7% on time. The 2pm–5pm window is the weakest at 70.8%, 23 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 SFO to DTW?
June is the weakest month at 68.0% on time, compared with 89.0% in April. 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
- DTW to SFO — the return legseparate record
- San Francisco International (SFO) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- United Airlines on SFO to DTW83.5%
- Delta Air Lines on SFO to DTW78.2%
- SFO to LAX, a related route73.9%
- ORD to DTW, a related route70.6%
- SFO to SEA, a related route73.7%
- United Airlines on-time record83.5%
- Delta Air Lines on-time record78.2%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. SFO to DTW and DTW 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.