Best Time to Fly CMH to IAD: On-Time Stats by Hour & Airline
John Glenn Columbus International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 85.2% of Columbus (CMH) to Washington (IAD) flights arrived on time (979 scheduled flights). That is 7.5 points above the national average of 77.6%.
Among 2 airlines, Republic Airways led with 88.7% on time and United Airlines was last with 79.7%.
Over 24 months, Saturday was the most reliable day (90% on time) and July the worst month (75%).
The cancellation rate was 0.9% (US average 1.8%).
CMH to IAD on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| Republic Airways | 88.7% | 55 min | 1.0% | 591 |
| United Airlines | 79.7% | 87 min | 0.8% | 388 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly CMH to IAD
On-time arrival % by scheduled departure hour (local time), 1,938 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | 93.2% | 0.9% | 673 |
| 10am–11am | 89.5% | 1.1% | 348 |
| 12pm–1pm | 91.8% | 0.0% | 50 |
| 1pm–2pm | 90.0% | 0.0% | 60 |
| 2pm–3pm | 71.6% | 0.5% | 212 |
| 3pm–4pm | 64.5% | 2.1% | 141 |
| 4pm–5pm | Limited data | 1 | |
| 7pm–8pm | 80.5% | 3.3% | 360 |
| 8pm–9pm | 80.2% | 2.1% | 93 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on CMH to IAD
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 25 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 83.0% | -3.3 pts | 0.0% | 59 |
| Summer peak (Jun 15 - Aug 15) | 78.2% | -8.2 pts | 5.3% | 266 |
| All other days | 86.3% | — | 0.9% | 1,588 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).