Route reliability record

MCI→ATL

Kansas City to Atlanta

Flights: 3,281
Period: July 2025 to June 2026
Distance: 692 mi
Carriers: 3

This route earns a 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 10 points better than the national rate of 77.6%. When something does go wrong the average delay runs a little over an hour. That rests on 3,281 flights, of which Delta Air Lines flew 2,759 at 90.1% on time.

Set against the rest of the country, this route's record is 10 points better than the US average of 77.6%. That gap is worth roughly 98 fewer late arrivals for every thousand flights.

On time

87.4%

Arrivals under 15 minutes late, of 3,227 completed flights

Avg delay

73 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

National rate is 1.81%

Best carrier

Delta

90.1% on time across 2,759 flights

These figures cover 3,281 flights between July 2025 and June 2026. The median arrival is 12 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 MCI to ATL

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 90.1% of the time; Southwest Airlines manages 78.8%. Sample sizes sit next to every figure, because a two-point gap across 365 flights means less than a ten-point one.

On-time performance by carrier on MCI to ATL
Airline	Flights	On time	Avg delay	Cancelled	Grade
Delta Air Lines	2,759	90.1%	74 min	1.52%	A
Southwest Airlines	365	78.8%	59 min	0.27%	B+
Frontier Airlinesthin sample	157	60.6%	86 min	1.27%	D

Delta leads Southwest by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

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 11 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am719 flights93.5%
8am–11am714 flights90.6%
11am–2pm705 flights85.6%
2pm–5pm531 flights82.6%
5pm–8pm609 flights83.0%
8pm–5am3 flights—

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 93.5% of the time, against 82.6% for the afternoon window. That is 11 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 719 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 13 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.

Darker means more delays. Figures are on-time percentages.August best, December worst

December is the weak month at 81.2% on time, against 93.7% in August. 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 307 flights.

Across the week, Tuesday is the strongest day at 92.3% on time and Sunday the weakest at 81.2%. 11 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. Late-arriving aircraft accounts for 44% of the 30,000 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.

Late-arriving aircraft
44%
Carrier
35%
National Airspace System
18%
Extreme weather
4%
Security
0%

44% 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 30,000 reported delay minutes here, that single category outweighs weather by 11 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 29,607 reported delay minutes.

The largest share of delay minutes, 35%, 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 30,000 delay minutes reported here.

Cancellations sit at 1.37% against a national 1.81%, which is ordinary. Diversions add another 0.27%.

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 692 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 82.8% on time across 3,281 flights, 5 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 5 points of difference.

The sample behind these figures is 3,281 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.

What to do with this

Booking this route

Put together: the calendar is the biggest lever here, not the carrier or the hour. August runs 93.7% on time and December 81.2%, a swing of 13 points. If the dates move at all, move them out of December before you think about anything else. 3,227 completed flights over 12 months sit behind that.

Common questions

MCI to ATL questions

How often is MCI to ATL delayed?

About one flight in eight arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 12.6% of the 3,281 flights in this analysis, against 22.4% nationally. Delayed flights are late by a little over an hour on average.

Which airline is most reliable on MCI to ATL?

Delta Air Lines leads at 90.1% on time across 2,759 flights. Southwest Airlines is at the other end on 78.8%, a gap of 11 points. Sample size matters as much as the percentage: a rate built from a few hundred flights moves around far more than one built from ten thousand.

What time of day has the fewest delays on MCI to ATL?

The 5am–8am departure window is the strongest at 93.5% on time. The 2pm–5pm window is the weakest at 82.6%, 11 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 MCI to ATL?

December is the weakest month at 81.2% on time, compared with 93.7% in August. Across the year that is 13 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.

Where to go next

Direction matters. MCI to ATL and ATL to MCI are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.

Key figures