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DelayAtlas

Route reliability record

DTWSFO

Detroit to San Francisco

Flights
1,799
Period
July 2025 to June 2026
Distance
2,079 mi
Carriers
2
C+GRADE

This route draws a C+. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 1,799 DTW to SFO flights, of which United Airlines flew 411 at 71.9% on time.

Best time to fly DTW to SFO: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 74.0% of the time and Tuesday flights 77.3%, against 67.7% for the route overall.

The national on-time rate over the same period is 77.6%, so this route runs 10 points behind the country as a whole. Across a thousand flights that is about 99 extra late arrivals.

Key figures

On time

67.7%

Arrivals under 15 minutes late, of 1,782 completed flights

Avg delay

66 min

Across delayed arrivals only, not all flights

Cancelled

0.89%

National rate is 1.81%

Best carrier

United

71.9% on time across 411 flights

These figures cover 1,799 flights between July 2025 and June 2026. Beyond the headline rate, 10.2% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.

Carrier by carrier

Which airline is most reliable on DTW 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.

On-time performance by carrier on DTW to SFO
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines41171.9%78 min1.22%C
Delta Air Lines1,38866.5%63 min0.79%C+

No carrier stands out. United tops the table at 71.9%, 5 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Flight by flight

Flights on DTW 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.

Best ways to make this trip

The most reliable ways to fly Detroit to San Francisco

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.

Most reliable ways to fly from DTW to SFO
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. DTWSFODetroit to San FranciscoUnited Airlines71.0%71.9%1.22%5pm–8pm, Tue
2. DTWSFODetroit to San FranciscoDelta Air Lines66.0%66.5%0.79%8am–11am, TueDL 361 08:30

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.

Plan this trip by month, day and time

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 21 points, against 5 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am206 flights68.6%
  • 8am–11am385 flights74.0%
  • 11am–2pm303 flights71.7%
  • 2pm–5pm281 flights66.9%
  • 5pm–8pm335 flights69.4%
  • 8pm–5am289 flights53.5%

Scale runs 45% to 80%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 53.5% on time, against 74.0% for the 8am–11am 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 385 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 51 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.

On-time rate by calendar month64J67F70M68A58M43J72J76A94S80O71N53D
Darker means more delays. Figures are on-time percentages.September best, June worst

June is the worst month at 42.6% on time, 51 points below September, the best at 93.8%. 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 77.3% on time and Monday the weakest at 62.3%. 15 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week62.3Mon77.3Tue71.9Wed66.3Thu64.0Fri69.4Sat63.9Sun
Monday: 62.3 percent on time. Tuesday: 77.3 percent on time. Wednesday: 71.9 percent on time. Thursday: 66.3 percent on time. Friday: 64.0 percent on time. Saturday: 69.4 percent on time. Sunday: 63.9 percent on time

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 38,000 reported delay minutes.

  • National Airspace System
    40%
  • Carrier
    37%
  • Late-arriving aircraft
    17%
  • Extreme weather
    5%
  • Security
    0%

40% 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 15,000 minutes out of 38,000, against a national NAS share of 21%. The split is drawn from 37,787 reported delay minutes.

The largest share of delay minutes, 37%, 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 14,000 of the 38,000 delay minutes reported here.

Cancellations are rare at 0.89%, 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

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.2% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

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 79.4% on time across 1,797 flights, 12 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 12 points of difference.

The sample behind these figures is 1,799 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. September runs 93.8% on time and June 42.6%, a swing of 51 points. If the dates move at all, move them out of June before you think about anything else. 1,782 completed flights over 12 months sit behind that.

Common questions

DTW to SFO questions

How often is DTW 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 32.3% of the 1,799 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

Which airline is most reliable on DTW to SFO?

United Airlines leads at 71.9% on time across 411 flights. Delta Air Lines is at the other end on 66.5%, 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 DTW to SFO?

The 8am–11am departure window is the strongest at 74.0% on time. The 8pm–5am window is the weakest at 53.5%, 21 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 DTW to SFO?

June is the weakest month at 42.6% on time, compared with 93.8% in September. Across the year that is 51 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

Direction matters. DTW to SFO and SFO to DTW 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.