Denver (DEN) to Buffalo (BUF): On-Time Performance
Data through May 2026
When you fly DEN to BUF matters as much as anything else about the booking: the route swung from 88% on-time in March 2026 to just 34% in May 2025. Across the full period the route averages 64% on-time against a national 78%. Morning departures also hold up better than evening ones (78% vs 59%), which matters most in the rough months.
- On-time
- 64%
- arrived <15 min late
- Avg delay
- 25 min
- completed flights
- Cancelled
- 0.4%
- Flights/day
- 1.7
- last 12 months
- Duration
- 3h 8m
- scheduled
- Distance
- 1,359 mi
Best airline from DEN to BUF
3 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| Frontier Airlinesmost reliable | 75% | 18 min | 0.7% | 139 |
| United Airlines | 66% | 30 min | 0.0% | 304 |
| Southwest Airlines | 61% | 23 min | 0.5% | 582 |
Monthly on-time trend
Best time to fly from DEN to BUF
Aim for departures around 10 a.m. (84% on-time); avoid 8 p.m. departures (52%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 60% | 28 min |
| Tuesday | 63% | 34 min |
| Wednesdaybest | 72% | 24 min |
| Thursday | 62% | 27 min |
| Friday | 62% | 21 min |
| Saturday | 68% | 19 min |
| Sunday | 63% | 25 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft58%
- Airline operations25%
- National airspace system15%
- Weather3%
Frequently asked questions
- How often are flights from DEN to BUF delayed?
- 36% of DEN–BUF flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 25 minutes.
- Which airline is most reliable from DEN to BUF?
- Frontier Airlines has the best on-time record on this route at 75%, based on 139 flights. 3 airlines flew DEN–BUF frequently enough to compare in this period.
- What is the best time of day to fly from DEN to BUF?
- Departures around 10 a.m. have the best record (84% on-time), while departures around 8 p.m. have the worst (52%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DEN to BUF?
- The scheduled DEN–BUF flight time averages 3h 8m over 1,359 miles. Actual arrival times vary — flights on this route land 15+ minutes late 36% of the time.
- How often are DEN to BUF flights cancelled?
- 0.4% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from DEN to BUF?
- May 2025 was the roughest month in this dataset, with only 34% of arrivals on time. The best was March 2026 at 88%. If your dates are flexible, that 54-point gap is worth planning around.
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Based on 1,025 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.