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DelayAtlas

Route reliability record

CMHMDW

Columbus to Chicago

Flights
1,251
Period
July 2025 to June 2026
Distance
283 mi
Carriers
1
BGRADE

This route lands a B, 3 points better than the national rate of 77.6%. About one flight in five 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 1,251 CMH to MDW flights, with a median arrival 5 minutes early.

Best time to fly CMH to MDW: a 5am–8am departure, ideally on a Tuesday. Flights in that window arrived on time 91.0% of the time and Tuesday flights 89.0%, against 80.8% for the route overall.

The US average over the same twelve months is 77.6%, so there is little to separate this route from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.

Key figures

On time

80.8%

Arrivals under 15 minutes late, of 1,232 completed flights

Avg delay

60 min

Across delayed arrivals only, not all flights

Cancelled

1.44%

National rate is 1.81%

Best carrier

Southwest

80.8% on time across 1,251 flights

These figures cover 1,251 flights between July 2025 and June 2026. The median arrival is 5 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 MDW

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.

On-time performance by carrier on CMH to MDW
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines1,25180.8%60 min1.44%B

Best ways to make this trip

The most reliable ways to fly Columbus to Chicago

Every airline on this route and on the routes between nearby airports, ranked by how often a scheduled flight actually operated and arrived on time. 4 of the top 5 use a different airport at one end.

Most reliable ways to fly from CMH to MDW
OptionAirlineSuccessOn timeCancelledBest departureMost punctual flight
1. CMHORDColumbus to ChicagoRepublic Airways81.8%83.6%2.18%5am–8am, TueYX 3524 06:00
2. CMHMDWColumbus to ChicagoSouthwest Airlines79.6%80.8%1.44%5am–8am, Tue
3. CMHORDColumbus to ChicagoEnvoy Air73.3%74.8%2.07%5am–8am, SatMQ 3572 08:20
4. CMHORDColumbus to ChicagoUnited Airlines65.1%66.3%1.81%11am–2pm, TueUA 1182 17:52
5. CMHORDColumbus to ChicagoSkyWest Airlines60.8%64.5%5.79%8am–11am, Tue

Success is the share of scheduled flights that operated and arrived less than 15 minutes late, so a cancelled flight counts against it. “(route)” means the best time comes from every carrier on the route rather than this airline alone.

Plan this trip by month, day and time

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 34 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–8am251 flights91.0%
  • 8am–11am179 flights90.4%
  • 11am–2pm221 flights88.1%
  • 2pm–5pm192 flights75.4%
  • 5pm–8pm244 flights77.2%
  • 8pm–5am164 flights57.1%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 57.1% on time, against 91.0% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 251 flights scheduled in it.

Across the year

When delays peak on this route

This route's year swings by 28 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.

On-time rate by calendar month79J83F66M81A82M79J72J90A94S85O84N74D
Darker means more delays. Figures are on-time percentages.September best, March worst

September is the best month on the calendar at 93.9% on time. Shoulder season thins the schedule and takes the summer weather with it, and the operation gets its margin back. July was the busiest month here, with 131 flights.

Across the week, Tuesday is the strongest day at 89.0% on time and Sunday the weakest at 71.4%. 18 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week76.2Mon89.0Tue88.0Wed82.4Thu79.1Fri80.5Sat71.4Sun
Monday: 76.2 percent on time. Tuesday: 89.0 percent on time. Wednesday: 88.0 percent on time. Thursday: 82.4 percent on time. Friday: 79.1 percent on time. Saturday: 80.5 percent on time. Sunday: 71.4 percent on time

Delay causes

Why this route gets delayed

One category carries most of the weight here. Late-arriving aircraft accounts for 57% of the 14,000 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
    57%
  • National Airspace System
    24%
  • Carrier
    17%
  • Extreme weather
    2%
  • Security
    0%

57% 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 14,000 reported delay minutes here, that single category outweighs weather by 37 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 14,057 reported delay minutes.

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 91.0% on time here.

Cancellations sit at 1.44% against a national 1.81%, which is ordinary. Diversions add another 0.08%.

Connections and stage length

What a delay here actually costs

6.1% 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 last about an hour, which a normal layover absorbs.

At 283 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 runs 81.4% on time across 1,247 flights, within half a point of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.

The sample behind these figures is 1,251 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.

Work out the risk of missing a connection in MDW after this flight

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 93.9% on time and March 65.9%, a swing of 28 points. If the dates move at all, move them out of March before you think about anything else. 1,232 completed flights over 12 months sit behind that.

Common questions

CMH to MDW questions

How often is CMH to MDW delayed?

About one flight in five arrives at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 19.2% of the 1,251 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.

How reliable is CMH to MDW compared with the rest of the country?

80.8% of flights arrive on time here against a national 77.6%, a difference of 3 points in its favour. That is worth a B on this site's grading scale.

What time of day has the fewest delays on CMH to MDW?

The 5am–8am departure window is the strongest at 91.0% on time. The 8pm–5am window is the weakest at 57.1%, 34 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 March delays on CMH to MDW?

March is the weakest month at 65.9% on time, compared with 93.9% in September. Across the year that is 28 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

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

Embed CMH to MDW’s on-time badge on your site

Paste this into a web page. The badge shows the current on-time rate, cancellation rate and grade, and updates every month. Preview it, or build a badge for another route or airport.

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.