Route reliability record
SLC→MCI
Salt Lake City to Kansas City
- Flights
- 1,012
- Period
- July 2025 to June 2026
- Distance
- 920 mi
- Carriers
- 1
This route earns an A. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 8 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 1,012 SLC to MCI flights, with a median arrival 10 minutes early.
Best time to fly SLC to MCI: a 8am–11am departure, ideally on a Tuesday. Flights in that window arrived on time 90.0% of the time and Tuesday flights 88.5%, against 85.3% for the route overall.
Set against the rest of the country, this route's record is 8 points better than the US average of 77.6%. That gap is worth roughly 77 fewer late arrivals for every thousand flights.
Key figures
On time
85.3%
Arrivals under 15 minutes late, of 997 completed flights
Avg delay
60 min
Across delayed arrivals only, not all flights
Cancelled
1.09%
National rate is 1.81%
Best carrier
Delta
85.3% on time across 1,012 flights
These figures cover 1,012 flights between July 2025 and June 2026. The median arrival is 10 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 MCI
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 |
|---|---|---|---|---|---|
| Delta Air Lines | 1,012 | 85.3% | 60 min | 1.09% | A |
Flight by flight
Flights on SLC to MCI
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 is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 1,012 flights.
- 5am–8am—
- 8am–11am365 flights90.0%
- 11am–2pm84 flights87.8%
- 2pm–5pm200 flights82.8%
- 5pm–8pm95 flights83.2%
- 8pm–5am268 flights80.5%
Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 90.0% of the time, against 80.5% for the overnight window. That is 10 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 365 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 18 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.
July is the worst month at 74.7% on time, 18 points below September, the best at 92.8%. 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 92 flights.
Across the week, Tuesday is the strongest day at 88.5% on time and Monday the weakest at 82.2%. 6 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 62% of the 8,771 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.
- 62%Carrier
- 32%Late-arriving aircraft
- 6%National Airspace System
- 1%Extreme weather
- 0%Security
The largest share of delay minutes, 62%, 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 5,395 of the 8,771 delay minutes reported here. The split is drawn from 8,771 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 90.0% on time here.
Cancellations sit at 1.09% against a national 1.81%, which is ordinary. Diversions add another 0.40%.
Connections and stage length
What a delay here actually costs
Badly late arrivals are rare here: only 4.4% 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 920 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 runs 87.3% on time across 1,012 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 1,012 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.
Work out the risk of missing a connection in MCI after this flight
What to do with this
Booking this route
Put together: treat all of this as provisional. 1,012 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 85.3% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 997 completed flights over 12 months sit behind that.
Common questions
SLC to MCI questions
How often is SLC to MCI delayed?
About one flight in seven arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.7% of the 1,012 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is SLC to MCI compared with the rest of the country?
85.3% of flights arrive on time here against a national 77.6%, a difference of 8 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 MCI?
The 8am–11am departure window is the strongest at 90.0% on time. The 8pm–5am window is the weakest at 80.5%, 10 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 MCI?
July is the weakest month at 74.7% on time, compared with 92.8% in September. Across the year that is 18 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
- MCI to SLC — the return legseparate record
- Salt Lake City International (SLC) delay statistics
- Kansas City International (MCI) delay statistics
- SLC to DEN, a related route77.8%
- DEN to MCI, a related route75.5%
- SLC to PHX, a related route83.9%
- Delta Air Lines on-time record85.3%
- 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 MCI and MCI 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.