Route reliability record
SLC→DTW
Salt Lake City to Detroit
- Flights
- 1,567
- Period
- July 2025 to June 2026
- Distance
- 1,481 mi
- Carriers
- 2
This route earns an A+. Close to nine flights in ten arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 12 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,567 SLC to DTW flights, with a median arrival 11 minutes early.
Best time to fly SLC to DTW: a 5am–8am departure, ideally on a Thursday. Flights in that window arrived on time 94.5% of the time and Thursday flights 91.0%, against 89.5% for the route overall.
Set against the rest of the country, this route's record is 12 points better than the US average of 77.6%. That gap is worth roughly 119 fewer late arrivals for every thousand flights.
Key figures
On time
89.5%
Arrivals under 15 minutes late, of 1,562 completed flights
Avg delay
64 min
Across delayed arrivals only, not all flights
Cancelled
0.19%
National rate is 1.81%
Best carrier
Delta
89.4% on time across 1,539 flights
These figures cover 1,567 flights between July 2025 and June 2026. The median arrival is 11 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 SLC to DTW
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.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Spirit Airlinesthin sample | 28 | 96.4% | 593 min | 0.00% | A+ |
| Delta Air Lines | 1,539 | 89.4% | 61 min | 0.19% | A+ |
Flight by flight
Flights on SLC 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.
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 13 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 flights94.5%
- 8am–11am365 flights93.1%
- 11am–2pm124 flights93.4%
- 2pm–5pm300 flights87.7%
- 5pm–8pm353 flights81.5%
- 8pm–5am60 flights84.7%
Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 94.5% of the time, against 81.5% for the evening window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5am–8am window is the busiest, with 365 flights scheduled in it.
Across the year
When delays peak on this route
Twelve months, one bar each, drawn from the same 1,567 flights. The strip shows how much of this route's record is set by the calendar rather than by the operation.
July is the worst month at 84.1% on time, 10 points below October, the best at 94.4%. 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 166 flights.
The day of the week is close to irrelevant here: 3 points separates the best day from the worst. Weekly demand peaks are not what drives the delays on this operation.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 56% of the 11,000 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.
- 56%Carrier
- 24%Late-arriving aircraft
- 19%National Airspace System
- 0%Extreme weather
The largest share of delay minutes, 56%, 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 5,917 of the 11,000 delay minutes reported here. The split is drawn from 10,531 reported delay minutes.
Cancellations are rare at 0.19%, 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
Badly late arrivals are rare here: only 3.7% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.
The 1,481 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 80.4% on time across 1,574 flights, 9 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 9 points of difference.
The sample behind these figures is 1,567 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: avoid the 5pm–8pm departure. It runs 81.5% on time against 94.5% for the 5am–8am slot, and that 13 points is the largest single thing you control here. Delta Air Lines is the strongest operator if the fares are close. 1,562 completed flights over 12 months sit behind that.
Common questions
SLC to DTW questions
How often is SLC to DTW delayed?
About one flight in ten arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 10.5% of the 1,567 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is SLC to DTW compared with the rest of the country?
89.5% of flights arrive on time here against a national 77.6%, a difference of 12 points in its favour. That is worth a A+ on this site's grading scale.
What time of day has the fewest delays on SLC to DTW?
The 5am–8am departure window is the strongest at 94.5% on time. The 5pm–8pm window is the weakest at 81.5%, 13 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 July delays on SLC to DTW?
July is the weakest month at 84.1% on time, compared with 94.4% in October. Across the year that is 10 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 SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- Detroit Metropolitan Wayne County (DTW) delay statistics
- SLC to DEN, a related route77.8%
- ORD to DTW, a related route70.6%
- SLC to PHX, a related route83.9%
- Spirit Airlines on-time record96.4%
- Delta Air Lines on-time record89.4%
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
Direction matters. SLC to DTW and DTW to SLC 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.