Airport month record
CMHMAY
John Glenn Columbus International in May 2026
- Departures
- 3,860
- Month
- May 2026
- National, same month
- 78.6%
- Carriers
- 10
Historical statistics for May 2026, not live status or a forecast for this year’s May. For today’s conditions at CMH, see live FAA status.
CMH in May lands a B, 5 points better than the national rate of 78.6%. About one flight in six 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 3,860 flights, of which Delta Air Lines flew 367 at 91.1% on time.
Delta Air Lines is the most reliable of the four carriers covered here at 91.1% on time across 367 flights.
Key figures
On time
83.4%
Arrivals under 15 minutes late, of 3,805 completed departures
Avg delay
65 min
Across delayed arrivals only, not all flights
Cancelled
1.22%
Nationally in May: 0.92%
Whole year
80.1%
CMH across all twelve months
These figures cover 3,860 departures from John Glenn Columbus International in May 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.
Against the year
May next to CMH's other months
Against CMH's own year, May ran 3 points better than the twelve-month rate of 80.1%, which makes it number three of twelve months, best first. Cancellations were unusually low for CMH in May, at 1.22% against 2.05% across the year. Either side of it, April ran 84.2% on time and June 81.0%, so this month sits in line with its neighbours.
| Month | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| July 2025 | 3,933 | 73.3% | 79 min | 3.41% | C− |
| August 2025 | 3,758 | 82.1% | 68 min | 1.41% | B |
| September 2025 | 3,726 | 85.2% | 67 min | 0.51% | A+ |
| October 2025 | 4,031 | 81.1% | 67 min | 0.72% | B+ |
| November 2025 | 3,641 | 79.9% | 77 min | 1.81% | B |
| December 2025 | 3,567 | 70.7% | 75 min | 1.68% | C |
| January 2026 | 3,296 | 81.6% | 78 min | 6.28% | B− |
| February 2026 | 3,231 | 82.9% | 75 min | 2.72% | B |
| March 2026 | 4,010 | 76.4% | 86 min | 3.24% | B− |
| April 2026 | 3,713 | 84.2% | 72 min | 0.51% | B+ |
| May 2026 (this page) | 3,860 | 83.4% | 65 min | 1.22% | B |
| June 2026 | 3,876 | 81.0% | 78 min | 1.57% | B |
Departure window
The best time of day to leave CMH in May
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am1,067 flights92.3%
- 8am–11am680 flights89.3%
- 11am–2pm623 flights86.1%
- 2pm–5pm616 flights75.7%
- 5pm–8pm672 flights72.7%
- 8pm–5am202 flights66.8%
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 92.3% of the time, against 66.8% for the overnight window. That is 26 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 1,067 flights scheduled in it.
Across the week, Tuesday is the strongest day at 86.7% on time and Wednesday the weakest at 77.9%. 9 points is a smaller lever than departure hour, but it is free.
Carrier by carrier
Which airlines ran best at CMH in May
The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 91.1% of the time; Southwest Airlines manages 78.5%. Sample sizes sit next to every figure, because a two-point gap across 1,045 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Republic Airways | 1,111 | 88.7% | 60 min | 1.44% | A |
| Southwest Airlines | 1,045 | 78.5% | 52 min | 0.48% | B+ |
| American Airlines | 383 | 82.7% | 98 min | 2.09% | B |
| Delta Air Lines | 367 | 91.1% | 84 min | 1.36% | A |
| United Airlinesthin sample | 322 | 74.2% | 75 min | 1.24% | C |
| Envoy Airthin sample | 242 | 89.2% | 49 min | 0.41% | A+ |
| PSA Airlinesthin sample | 163 | 80.6% | 80 min | 1.84% | B |
| SkyWest Airlinesthin sample | 135 | 82.6% | 90 min | 2.22% | B |
| Frontier Airlinesthin sample | 46 | 68.9% | 38 min | 2.17% | C |
| Alaska Airlinesthin sample | 44 | 72.7% | 44 min | 0.00% | C+ |
The spread between Delta and Southwest is 13 points, wide enough that it should decide the booking. On a hundred trips that is 13 more arrivals inside the on-time window.
Route by route
Busiest routes out of CMH in May
| Route | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| CMH to ORD · Chicago | 459 | 83.9% | 76 min | 1.31% | B |
| CMH to ATL · Atlantathin sample | 270 | 87.5% | 79 min | 1.85% | A |
| CMH to LGA · New Yorkthin sample | 251 | 85.7% | 73 min | 2.39% | A |
| CMH to CLT · Charlottethin sample | 195 | 85.6% | 46 min | 0.51% | A+ |
| CMH to EWR · Newarkthin sample | 179 | 89.7% | 63 min | 2.23% | A |
| CMH to DCA · Washingtonthin sample | 178 | 72.7% | 75 min | 1.12% | C |
| CMH to BOS · Bostonthin sample | 168 | 87.4% | 47 min | 0.60% | A+ |
| CMH to MCO · Orlandothin sample | 152 | 78.9% | 35 min | 1.97% | B |
| CMH to DEN · Denverthin sample | 152 | 81.6% | 54 min | 0.00% | B+ |
| CMH to DFW · Dallas-Fort Worththin sample | 152 | 75.3% | 88 min | 3.95% | B− |
| CMH to DTW · Detroitthin sample | 150 | 90.6% | 63 min | 0.67% | A+ |
| CMH to PHL · Philadelphiathin sample | 138 | 85.3% | 108 min | 1.45% | A |
| CMH to JFK · New Yorkthin sample | 112 | 94.6% | 32 min | 0.89% | A+ |
| CMH to PHX · Phoenixthin sample | 111 | 79.6% | 63 min | 1.80% | B |
| CMH to MSP · Minneapolisthin sample | 104 | 93.2% | 95 min | 0.96% | A+ |
| CMH to MIA · Miamithin sample | 96 | 93.8% | 42 min | 0.00% | A+ |
| CMH to BNA · Nashvillethin sample | 92 | 76.1% | 47 min | 0.00% | B+ |
| CMH to MDW · Chicagothin sample | 92 | 81.5% | 57 min | 0.00% | B+ |
| CMH to BWI · Baltimorethin sample | 89 | 86.4% | 76 min | 1.12% | A |
| CMH to LAS · Las Vegasthin sample | 87 | 77.0% | 71 min | 0.00% | B+ |
| CMH to TPA · Tampathin sample | 85 | 84.5% | 44 min | 0.00% | B+ |
| CMH to IAD · Washingtonthin sample | 69 | 80.9% | 75 min | 1.45% | B |
| CMH to LAX · Los Angelesthin sample | 61 | 73.8% | 101 min | 0.00% | C+ |
| CMH to STL · St. Louisthin sample | 56 | 82.1% | 65 min | 0.00% | B+ |
| CMH to DAL · Dallasthin sample | 48 | 82.2% | 41 min | 4.17% | B− |
Delay causes
What held CMH up in May
One category carries most of the weight here. Late-arriving aircraft accounts for 43% of the 41,000 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.
- 43%Late-arriving aircraft
- 28%National Airspace System
- 27%Carrier
- 3%Extreme weather
- 0%Security
43% 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 41,000 reported delay minutes here, that single category outweighs weather by 15 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 41,152 reported delay minutes.
Cancellations sit at 1.22% against a national 0.92%, which is ordinary. Diversions add another 0.21%.
5.1% of arrivals land an hour or more late, close to the national 7.1%. 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.
What to do with this
Flying from CMH in May
For a May trip through CMH: this is one of the better months to be flying from here, 83.4% on time with 1.22% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.
Related
Where to go next
- John Glenn Columbus International (CMH), the whole year
- CMH in July73.3%
- CMH in August82.1%
- CMH in September85.2%
- CMH in October81.1%
- CMH in November79.9%
- CMH in December70.7%
- CMH in January81.6%
- CMH in February82.9%
- CMH in March76.4%
- CMH in April84.2%
- CMH in June81.0%
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.