Skip to content
DelayAtlas

Carrier route record

UASFODTW

United Airlines · San Francisco to Detroit

Flights
409
Period
July 2025 to June 2026
Share of route
23%
Carriers
2
B+GRADE

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

United on SFO to DTW lands a B+, 6 points better than the national rate of 77.6%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about 55 minutes on average. That is a workable record, not a spotless one. That rests on 409 flights, with a median arrival 7 minutes early.

Set against the rest of the country, United's SFO to DTW record is 6 points better than the US average of 77.6%. That gap is worth roughly 59 fewer late arrivals for every thousand flights.

Key figures

On time

83.5%

Arrivals under 15 minutes late, of 406 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

0.73%

National rate is 1.81%

Whole route

79.4%

Every carrier on SFO to DTW, 1,797 flights

These figures cover 409 flights between July 2025 and June 2026. The median arrival is 7 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

United against every carrier on SFO to DTW

United flew 409 of the 1,797 flights on SFO to DTW, about 23% of it. Its 83.5% on time is 4 points better than the route as a whole, which runs 79.4%. Ranked by on-time rate it is first 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
AirlineFlightsOn timeAvg delayCancelledGrade
United Airlines (this page)40983.5%55 min0.73%B+
Delta Air Lines1,38878.2%53 min0.86%B+

Departure window

When United runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 16 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–8am
  • 8am–11am149 flights89.9%
  • 11am–2pm153 flights82.7%
  • 2pm–5pm40 flights80.0%
  • 5pm–8pm2 flights
  • 8pm–5am65 flights73.8%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

Book the morning departure. Flights leaving between 8am–11am arrive on time 89.9% of the time, against 73.8% for the overnight window. That is 16 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 153 flights scheduled in it.

Across the year

United on SFO to DTW through the year

On-time rate by calendar month71JF81M93A90M94J68J83A90S94O80N74D
Darker means more delays. Figures are on-time percentages.June best, July worst

July is the worst month at 68.0% on time, 26 points below June, the best at 93.5%. 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 52 flights.

Across the week, Saturday is the strongest day at 89.7% on time and Thursday the weakest at 79.0%. 11 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week85.5Mon80.8Tue87.1Wed79.0Thu80.0Fri89.7Sat82.3Sun
Monday: 85.5 percent on time. Tuesday: 80.8 percent on time. Wednesday: 87.1 percent on time. Thursday: 79.0 percent on time. Friday: 80.0 percent on time. Saturday: 89.7 percent on time. Sunday: 82.3 percent on time

Delay causes

Why United runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 54% of the 3,655 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
    54%
  • Carrier
    33%
  • National Airspace System
    13%

54% 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 3,655 reported delay minutes here, that single category outweighs weather by 54 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 3,655 reported delay minutes.

The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 89.9% on time here.

Cancellations are rare at 0.73%, 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

5.7% 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 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 71.9% on time across 411 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.

One caution: this is a thin sample. 409 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking United on SFO to DTW

Put together: treat all of this as provisional. 409 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 83.5% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 406 completed flights over 12 months sit behind that.

Related

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.