Carrier route record

DLSFO→DTW

Delta Air Lines · San Francisco to Detroit

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 SFO to DTW lands a B+, level with the national rate of 77.6%. Roughly 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 1,388 flights, with a median arrival 5 minutes early.

The US average over the same twelve months is 77.6%, so there is little to separate Delta on SFO to DTW from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

On time

78.2%

Arrivals under 15 minutes late, of 1,373 completed flights

Avg delay

53 min

Across delayed arrivals only, not all flights

Cancelled

0.86%

National rate is 1.81%

Whole route

79.4%

Every carrier on SFO to DTW, 1,797 flights

These figures cover 1,388 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

Delta against every carrier on SFO to DTW

Delta flew 1,388 of the 1,797 flights on SFO to DTW, most of the route. Its 78.2% on time is about level with the route as a whole at 79.4%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from United at 83.5% to Delta at 78.2%.

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 SFO to DTW
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	409	83.5%	55 min	0.73%	B+
Delta Air Lines (this page)	1,388	78.2%	53 min	0.86%	B+

Flight by flight

Delta flight numbers on SFO to DTW

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 24 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–8am365 flights93.7%
8am–11am2 flights—
11am–2pm363 flights76.8%
2pm–5pm263 flights69.4%
5pm–8pm—
8pm–5am395 flights71.2%

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 69.4% for the afternoon window. That is 24 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8pm–5am window is the busiest, with 395 flights scheduled in it.

Across the year

Delta on SFO to DTW through the year

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

June is the worst month at 58.9% on time, 30 points below March, the best at 89.2%. 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 85.4% on time and Sunday the weakest at 74.4%. 11 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Delta runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 16,000 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.

Late-arriving aircraft
51%
Carrier
31%
National Airspace System
16%
Extreme weather
1%

51% 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 16,000 reported delay minutes here, that single category outweighs weather by 51 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 15,807 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 0.86%, 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

6.6% 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 66.5% on time across 1,388 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 1,388 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 SFO to DTW

Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 89.2% on time and June 58.9%, a swing of 30 points. If the dates move at all, move them out of June before you think about anything else. 1,373 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