Route reliability record
CMH→ATL
Columbus to Atlanta
- Flights
- 3,160
- Period
- July 2025 to June 2026
- Distance
- 447 mi
- Carriers
- 4
This route earns a 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 an hour and a half. That rests on 3,160 flights, with a median arrival 12 minutes early.
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 83 fewer late arrivals for every thousand flights.
Key figures
On time
85.9%
Arrivals under 15 minutes late, of 3,103 completed flights
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
1.52%
National rate is 1.81%
Best carrier
Delta
88.2% on time across 2,693 flights
These figures cover 3,160 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 CMH to ATL
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 | 2,693 | 88.2% | 92 min | 1.56% | A |
| Spirit Airlinesthin sample | 7 | 85.7% | 206 min | 0.00% | A+ |
| Southwest Airlinesthin sample | 326 | 81.7% | 46 min | 0.92% | B+ |
| Frontier Airlinesthin sample | 134 | 51.1% | 65 min | 2.24% | F |
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 20 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–8am704 flights91.3%
- 8am–11am588 flights89.4%
- 11am–2pm841 flights84.3%
- 2pm–5pm448 flights85.7%
- 5pm–8pm517 flights79.3%
- 8pm–5am62 flights71.7%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the early departure. Flights leaving between 5am–8am arrive on time 91.3% of the time, against 71.7% for the overnight window. That is 20 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 11am–2pm window is the busiest, with 841 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 15 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 78.4% on time, against 93.5% 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 299 flights.
Across the week, Wednesday is the strongest day at 93.4% on time and Monday the weakest at 80.3%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 36,000 reported delay minutes.
- 40%Carrier
- 37%Late-arriving aircraft
- 21%National Airspace System
- 3%Extreme weather
37% 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 36,000 reported delay minutes here, that single category outweighs weather by 14 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 35,768 reported delay minutes.
The largest share of delay minutes, 40%, 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 14,000 of the 36,000 delay minutes reported here.
Cancellations sit at 1.52% against a national 1.81%, which is ordinary. Diversions add another 0.28%.
Connections and stage length
What a delay here actually costs
5.5% 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 are the an hour and a half kind, which a normal layover absorbs.
At 447 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.
The return leg is a different operation and performs like one: it runs 80.5% on time across 3,159 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 3,160 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. September runs 93.5% on time and December 78.4%, a swing of 15 points. If the dates move at all, move them out of December before you think about anything else. 3,103 completed flights over 12 months sit behind that.
Common questions
CMH to ATL questions
How often is CMH to ATL delayed?
About one flight in seven arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 14.1% of the 3,160 flights in this analysis, against 22.4% nationally. Delayed flights are late by an hour and a half on average.
How reliable is CMH to ATL compared with the rest of the country?
85.9% 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 CMH to ATL?
The 5am–8am departure window is the strongest at 91.3% on time. The 8pm–5am window is the weakest at 71.7%, 20 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 CMH to ATL?
December is the weakest month at 78.4% on time, compared with 93.5% in September. Across the year that is 15 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
- ATL to CMH — the return legseparate record
- John Glenn Columbus International (CMH) delay statistics
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- Delta Air Lines on-time record88.2%
- Spirit Airlines on-time record85.7%
- Southwest Airlines on-time record81.7%
- Why the first flight of the morning is statistically safest
- The best time of day to fly, according to 7.04 million flight records
Direction matters. CMH to ATL and ATL to CMH 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.