Route reliability record
SLC→MCI
Salt Lake City to Kansas City
- Flights
- 1,005
- Period
- September 2025 to August 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 77.3%. When something does go wrong the average delay runs about an hour. That rests on 1,005 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 Saturday. Flights in that window arrived on time 89.2% of the time and Saturday flights 88.2%, against 85.4% for the route overall.
Set against the rest of the country, this route's record is 8 points better than the US average of 77.3%. That gap is worth roughly 81 fewer late arrivals for every thousand flights.
Key figures
On time
85.4%
Arrivals under 15 minutes late, of 992 completed flights
Avg delay
56 min
Across delayed arrivals only, not all flights
Cancelled
0.90%
National rate is 1.89%
Best carrier
Delta
85.4% on time across 1,005 flights
These figures cover 1,005 flights between September 2025 and August 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.
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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 | 1,005 | 85.4% | 56 min | 0.90% | 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.
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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 1,005 flights.
- 5am–8am—
- 8am–11am365 flights89.2%
- 11am–2pm116 flights85.1%
- 2pm–5pm161 flights83.6%
- 5pm–8pm91 flights89.0%
- 8pm–5am272 flights80.1%
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 89.2% of the time, against 80.1% for the overnight window. That is 9 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.
Explore
Filter SLC to MCI by airline, time, month and day
Pick a breakdown and a carrier. The dashed mark on each row is the same slice for every US flight.
On SLC to MCI, the best departure window is 8am–11am at 89.2% on time and the worst is 8pm–5am at 80.1%, a real gap of 9.1 points. All US flights leaving 8am–11am ran 83.9%.
- 5–8am—
- 8–11am89.2%
- 11am–2pm85.1%
- 2–5pm83.6%
- 5–8pm89.0%
- 8pm–5am80.1%
best all US flightsScale 60% to 95%. Cells under 30 flights show a dash.
Across the year
When delays peak on this route
This route's year swings by 14 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 78.7% on time, against 92.8% 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. October was the busiest month here, with 91 flights.
Across the week, Saturday is the strongest day at 88.2% on time and Monday the weakest at 81.2%, a spread of 7 points.
Delay causes
Why this route gets delayed
Carrier accounts for 57% of the 8,179 delay minutes carriers reported here, and the remaining four split what is left.
- 57%Carrier
- 35%Late-arriving aircraft
- 6%National Airspace System
- 2%Extreme weather
- 0%Security
35% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 8,179 reported delay minutes here, that single category outweighs weather by 20 to one. The split is drawn from 8,179 reported delay minutes.
The largest share of delay minutes, 57%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 4,664 of the 8,179 delay minutes reported here.
Cancellations sit at 0.90% against a national 1.89%, 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 8.3% 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.
The return leg runs 87.0% on time across 1,005 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. 1,005 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. 1,005 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 85.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 992 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 14.6% of the 1,005 flights in this analysis, against 22.7% nationally. Delayed flights are late by about an hour on average.
How reliable is SLC to MCI compared with the rest of the country?
85.4% of flights arrive on time here against a national 77.3%, 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 89.2% on time. The 8pm–5am window is the weakest at 80.1%, 9 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 SLC to MCI?
December is the weakest month at 78.7% on time, compared with 92.8% in September. Across the year that is 14 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 route79.0%
- DEN to MCI, a related route76.5%
- SLC to PHX, a related route83.5%
- Delta Air Lines on-time record85.4%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.05 million flight records
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.