Best Time to Fly DEN to BUF: On-Time Stats by Hour & Airline
Denver International → Buffalo Niagara International
Data through July 2026 · Last updated October 18, 2026
587 flights were scheduled from Denver (DEN) to Buffalo (BUF) in the last 12 months, and 67.7% of those that flew arrived on time, 9.9 points below the US average of 77.6%.
Among 3 airlines, Frontier Airlines led with 82.9% on time and Southwest Airlines was last with 60.5%.
Over 24 months, Wednesday was the most reliable day (69% on time) and July the worst month (48%).
The cancellation rate was 0.2% (US average 1.8%).
DEN to BUF 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 |
|---|---|---|---|---|
| Frontier Airlines | 82.9% | 44 min | 0.0% | 35 |
| United Airlines | 72.1% | 83 min | 0.0% | 294 |
| Southwest Airlines | 60.5% | 45 min | 0.4% | 258 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly DEN to BUF
On-time arrival % by scheduled departure hour (local time), 1,066 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 6am–7am | Limited data | 5 | |
| 7am–8am | Limited data | 13 | |
| 8am–9am | Limited data | 25 | |
| 9am–10am | 81.6% | 0.0% | 49 |
| 10am–11am | 83.7% | 0.0% | 49 |
| 11am–12pm | 74.6% | 0.0% | 63 |
| 12pm–1pm | 52.3% | 0.0% | 44 |
| 1pm–2pm | 65.9% | 0.0% | 44 |
| 2pm–3pm | 56.2% | 0.0% | 32 |
| 3pm–4pm | Limited data | 11 | |
| 4pm–5pm | 79.0% | 2.6% | 39 |
| 5pm–6pm | 60.3% | 0.0% | 475 |
| 6pm–7pm | 67.7% | 3.0% | 67 |
| 7pm–8pm | 52.2% | 0.0% | 137 |
| 8pm–9pm | Limited data | 13 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on DEN to BUF
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 | 23 | ||
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 25 | ||
| Summer peak (Jun 15 - Aug 15) | 52.2% | -16.5 pts | 0.3% | 297 |
| All other days | 68.7% | — | 0.3% | 721 |
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).