Carrier route record

DLDTW→SFO

Delta Air Lines · Detroit to San Francisco

Flights: 1,388
Period: July 2025 to June 2026
Share of route: 77%
Carriers: 2

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.

Delta on DTW to SFO 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 1,388 flights, with a median arrival 3 minutes late.

The national on-time rate over the same period is 77.6%, so Delta on DTW to SFO runs 11 points behind the country as a whole. Across a thousand flights that is about 111 extra late arrivals.

On time

66.5%

Arrivals under 15 minutes late, of 1,377 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

0.79%

National rate is 1.81%

Whole route

67.7%

Every carrier on DTW to SFO, 1,799 flights

These figures cover 1,388 flights between July 2025 and June 2026. Beyond the headline rate, 10.1% 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

Delta against every carrier on DTW to SFO

Delta flew 1,388 of the 1,799 flights on DTW to SFO, most of the route. Its 66.5% on time is about level with the route as a whole at 67.7%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 71.9% to Delta at 66.5%.

Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.

On-time performance by carrier on DTW to SFO
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	411	71.9%	78 min	1.22%	C
Delta Air Lines (this page)	1,388	66.5%	63 min	0.79%	C+

Flight by flight

Delta flight numbers on DTW to SFO

Departure window

When Delta runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am2 flights—
8am–11am363 flights73.3%
11am–2pm303 flights71.7%
2pm–5pm281 flights66.9%
5pm–8pm150 flights64.4%
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 73.3% 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 363 flights scheduled in it.

Across the year

Delta on DTW to SFO through the year

Darker means more delays. Figures are on-time percentages.September best, June worst

June is the worst month at 40.8% on time, 53 points below September, the best at 93.9%. 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 138 flights.

Across the week, Tuesday is the strongest day at 75.4% on time and Monday the weakest at 60.3%. 15 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

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 29,000 reported delay minutes.

National Airspace System
40%
Carrier
40%
Late-arriving aircraft
13%
Extreme weather
6%
Security
0%

The largest share of delay minutes, 40%, 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 29,000 delay minutes reported here. The split is drawn from 28,867 reported delay minutes.

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 12,000 minutes out of 29,000, against a national NAS share of 21%.

Cancellations are rare at 0.79%, 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 costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.1% 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 78.2% on time across 1,388 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 1,388 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.

What to do with this

Booking Delta on DTW to SFO

Put together: the calendar is the biggest lever here, not the carrier or the hour. September runs 93.9% on time and June 40.8%, a swing of 53 points. If the dates move at all, move them out of June before you think about anything else. 1,377 completed flights over 12 months sit behind that.

Where to go next

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.

Key figures