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DelayAtlas

Airport month record

CMHSEP

John Glenn Columbus International in September 2025

Departures
3,726
Month
September 2025
National, same month
83.4%
Carriers
11
A+GRADE

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at CMH, see live FAA status.

CMH in September 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 2 points better than the national rate of 83.4%. When something does go wrong the average delay runs about an hour. That rests on 3,726 flights, of which Southwest Airlines flew 870 at 87.8% on time.

Key figures

On time

85.2%

Arrivals under 15 minutes late, of 3,700 completed departures

Avg delay

67 min

Across delayed arrivals only, not all flights

Cancelled

0.51%

Nationally in September: 0.51%

Whole year

80.1%

CMH across all twelve months

These figures cover 3,726 departures from John Glenn Columbus International in September 2025. 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

September next to CMH's other months

Against CMH's own year, September ran 5 points better than the twelve-month rate of 80.1%, which makes it the best of the twelve months in the data. Cancellations were unusually low for CMH in September, at 0.51% against 2.05% across the year. Either side of it, August ran 82.1% on time and October 81.1%, so a trip moved by a few weeks would have landed in a worse stretch.

CMH month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20253,93373.3%79 min3.41%C−
August 20253,75882.1%68 min1.41%B
September 2025 (this page)3,72685.2%67 min0.51%A+
October 20254,03181.1%67 min0.72%B+
November 20253,64179.9%77 min1.81%B
December 20253,56770.7%75 min1.68%C
January 20263,29681.6%78 min6.28%B−
February 20263,23182.9%75 min2.72%B
March 20264,01076.4%86 min3.24%B−
April 20263,71384.2%72 min0.51%B+
May 20263,86083.4%65 min1.22%B
June 20263,87681.0%78 min1.57%B

Departure window

The best time of day to leave CMH in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 20 points, against 2 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am913 flights93.7%
  • 8am–11am595 flights93.3%
  • 11am–2pm746 flights86.5%
  • 2pm–5pm583 flights76.0%
  • 5pm–8pm723 flights74.1%
  • 8pm–5am166 flights82.9%

Scale runs 65% to 100%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 93.7% of the time, against 74.1% for the evening 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 5am–8am window is the busiest, with 913 flights scheduled in it.

Across the week, Tuesday is the strongest day at 88.9% on time and Thursday the weakest at 80.7%. 8 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week83.5Mon88.9Tue88.9Wed80.7Thu85.4Fri86.6Sat83.0Sun
Monday: 83.5 percent on time. Tuesday: 88.9 percent on time. Wednesday: 88.9 percent on time. Thursday: 80.7 percent on time. Friday: 85.4 percent on time. Saturday: 86.6 percent on time. Sunday: 83.0 percent on time

Carrier by carrier

Which airlines ran best at CMH in September

The two carriers here are closely matched: 2 points separate the best from the worst. At that spread, schedule and price are better tie-breakers than reliability. Sample sizes are shown so you can see which rows are worth weighing.

Carriers at CMH in September 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Republic Airways1,08585.8%67 min1.11%A
Southwest Airlines87087.8%51 min0.11%A+
American Airlinesthin sample35286.4%111 min1.14%A
United Airlinesthin sample33976.9%56 min0.00%B+
Delta Air Linesthin sample33293.1%94 min0.00%A+
Envoy Airthin sample22788.5%89 min0.00%A+
Spirit Airlinesthin sample20576.5%64 min0.49%B+
PSA Airlinesthin sample14277.5%58 min0.00%B+
SkyWest Airlinesthin sample9276.9%56 min1.09%B
Alaska Airlinesthin sample4889.6%52 min0.00%A+
Frontier Airlinesthin sample3467.6%74 min0.00%C+

No carrier stands out. Southwest tops the table at 87.8%, 2 points clear of the bottom, which is inside the range this kind of sample moves year to year.

Route by route

Busiest routes out of CMH in September

Routes from CMH in September 2025
RouteFlightsOn timeAvg delayCancelledGrade
CMH to ORD · Chicago41178.3%70 min0.24%B+
CMH to ATL · Atlantathin sample27793.5%93 min0.00%A+
CMH to LGA · New Yorkthin sample26087.8%80 min1.15%A
CMH to EWR · Newarkthin sample20080.9%67 min3.00%B
CMH to BOS · Bostonthin sample18066.1%63 min1.67%C
CMH to DCA · Washingtonthin sample17181.9%55 min0.00%B+
CMH to MCO · Orlandothin sample16885.1%52 min0.00%A+
CMH to CLT · Charlottethin sample15991.8%59 min0.00%A+
CMH to JFK · New Yorkthin sample15091.3%73 min0.67%A+
CMH to DEN · Denverthin sample14685.5%52 min0.00%A+
CMH to IAD · Washingtonthin sample13691.2%41 min0.00%A+
CMH to DFW · Dallas-Fort Worththin sample12787.8%148 min1.57%A
CMH to PHL · Philadelphiathin sample12678.4%59 min0.79%B+
CMH to MDW · Chicagothin sample11593.9%33 min0.00%A+
CMH to MSP · Minneapolisthin sample9784.5%86 min0.00%B+
CMH to DTW · Detroitthin sample9591.6%71 min0.00%A+
CMH to BWI · Baltimorethin sample9088.9%49 min0.00%A+
CMH to BNA · Nashvillethin sample8887.5%44 min0.00%A+
CMH to LAS · Las Vegasthin sample8481.0%44 min0.00%B+
CMH to PHX · Phoenixthin sample7387.3%117 min1.37%A
CMH to FLL · Fort Lauderdalethin sample6779.1%55 min0.00%B+
CMH to TPA · Tampathin sample6296.8%71 min0.00%A+
CMH to MIA · Miamithin sample6090.0%49 min0.00%A+
CMH to STL · St. Louisthin sample5694.5%38 min1.79%A
CMH to IAH · Houstonthin sample5676.8%113 min0.00%B+

Delay causes

What held CMH up in September

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 37,000 reported delay minutes.

  • Carrier
    34%
  • Late-arriving aircraft
    32%
  • National Airspace System
    30%
  • Extreme weather
    3%
  • Security
    0%

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.7% on time here. The split is drawn from 36,833 reported delay minutes.

Cancellations are rare at 0.51%, below the national 0.51% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

5.0% of arrivals land an hour or more late, close to the national 5.4%. 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 September

For a September trip through CMH: this is one of the better months to be flying from here, 85.2% on time with 0.51% 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

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.