Route reliability record
DTW→SLC
Detroit to Salt Lake City
- Flights
- 1,574
- Period
- July 2025 to June 2026
- Distance
- 1,481 mi
- Carriers
- 2
This route lands a B+, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 1,574 DTW to SLC flights, with a median arrival 3 minutes early.
Best time to fly DTW to SLC: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 95.4% of the time and Tuesday flights 84.9%, against 80.4% for the route overall.
The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.4%
Arrivals under 15 minutes late, of 1,571 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
0.19%
National rate is 1.81%
Best carrier
Delta
80.0% on time across 1,546 flights
These figures cover 1,574 flights between July 2025 and June 2026. The median arrival is 3 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 DTW to SLC
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 | 100.0% | — | 0.00% | A+ |
| Delta Air Lines | 1,546 | 80.0% | 59 min | 0.19% | B+ |
Flight by flight
Flights on DTW to SLC
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 29 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–8am65 flights95.4%
- 8am–11am396 flights89.8%
- 11am–2pm365 flights87.1%
- 2pm–5pm31 flights77.4%
- 5pm–8pm373 flights74.2%
- 8pm–5am344 flights66.6%
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 95.4% of the time, against 66.6% for the overnight window. That is 29 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 396 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 37 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.
December is the weak month at 55.6% on time, against 92.7% in September. Winter delays cluster: a single storm system can account for most of a month's shortfall, so an average December hides both very good weeks and genuinely unflyable days. July was the busiest month here, with 167 flights.
Across the week, Tuesday is the strongest day at 84.9% on time and Saturday the weakest at 77.9%. 7 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Carrier accounts for 55% of the 18,000 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.
- 55%Carrier
- 22%Late-arriving aircraft
- 19%National Airspace System
- 4%Extreme weather
The largest share of delay minutes, 55%, 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 10,000 of the 18,000 delay minutes reported here. The split is drawn from 18,164 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
6.0% 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 an hour, which a normal layover absorbs.
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 89.5% on time across 1,567 flights, 9 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 9 points of difference.
The sample behind these figures is 1,574 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 SLC 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 92.7% on time and December 55.6%, a swing of 37 points. If the dates move at all, move them out of December before you think about anything else. 1,571 completed flights over 12 months sit behind that.
Common questions
DTW to SLC questions
How often is DTW to SLC delayed?
About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 19.6% of the 1,574 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is DTW to SLC compared with the rest of the country?
80.4% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B+ on this site's grading scale.
What time of day has the fewest delays on DTW to SLC?
The 5am–8am departure window is the strongest at 95.4% on time. The 8pm–5am window is the weakest at 66.6%, 29 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 December delays on DTW to SLC?
December is the weakest month at 55.6% on time, compared with 92.7% in September. Across the year that is 37 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
- SLC to DTW — the return legseparate record
- Detroit Metropolitan Wayne County (DTW) delay statistics
- Salt Lake City International (SLC) delay statistics
- DTW to ORD, a related route72.0%
- DEN to SLC, a related route77.5%
- DTW to ATL, a related route79.0%
- Spirit Airlines on-time record100.0%
- Delta Air Lines on-time record80.0%
- 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. DTW to SLC and SLC 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.