Routes › Buffalo (BUF) › BUF to DEN
Route · 12 months to July 2026
Buffalo to Denver: on-time record
Buffalo Niagara International to Denver International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
In the 12 months to July 2026, reporting carriers scheduled 586 flights from Buffalo (BUF) to Denver (DEN), a distance of 1,359 miles. 74.7% of them arrived within 15 minutes of schedule.
That is 1.3 points below the national on-time share of 76.0% for the same period and 0.8 points below the 75.5% recorded for all departures from BUF. Flights that did arrive were 8.1 min late on average, and 0.2% of scheduled flights were cancelled (national: 1.8%).
2 reporting carriers flew the route at least 60 times. United Airlines had the highest on-time share at 84.3% of 293 flights; Southwest Airlines had the lowest at 65.5% of 258.
By scheduled departure hour (local time at BUF), flights leaving from 7 am to 8 am had the highest on-time share, 89.5%; those leaving from 4 pm to 5 pm had the lowest, 33.8%.
The on-time share is down 7.1 points on the previous 12 months (81.8%); cancellations moved from 0.2% to 0.2%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, late-arriving aircraft 36%, air carrier 36% and national aviation system 26%.
- On time 74.7%
- Arrived 15+ minutes late 25.1%
- Cancelled 0.2%
- Diverted 0.0%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| UA United Airlines | 293 | 50% | 84.3% | 4.9 min | 0.0% |
| WN Southwest Airlines | 258 | 44% | 65.5% | 12.1 min | 0.4% |
| F9 Frontier Airlines | 35 | 6% | 62.9% | 6.0 min | 0.0% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | BUF to DEN | All departures from BUF | All arrivals at DEN | All reported flights |
|---|---|---|---|---|
| Arrived on time | 74.7% | 75.5% | 78.4% | 76.0% |
| Arrived 15+ minutes late | 25.1% | 21.7% | 20.5% | 21.9% |
| Cancelled | 0.2% | 2.6% | 0.8% | 1.8% |
| Diverted | 0.0% | 0.2% | 0.3% | 0.3% |
| Average arrival delay | 8.1 min | 9.7 min | 6.2 min | 8.1 min |
| Delay minutes per 100 flights | 1,531 | 1,827 | 1,561 | 1,684 |
| Scheduled flights | 586 | 20,726 | 319,190 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, DEN to BUF, recorded 67.5% on time across 587 flights in the same period.
Month by month
Year on year: on time 74.7% against 81.8% (−7.1 pts), cancelled 0.2% against 0.2%, flights 586 against 479.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 57 | 66.7% | 10.5% | -1.9 min | 3 |
| Feb | 84 | 71.4% | 0.0% | 8.2 min | 3 |
| Mar | 93 | 79.6% | 0.0% | 9.1 min | 3 |
| Apr | 105 | 72.4% | 0.0% | 8.0 min | 3 |
| May | 129 | 69.0% | 0.8% | 10.8 min | 3 |
| Jun | 190 | 74.7% | 0.5% | 5.4 min | 3 |
| Jul | 200 | 76.0% | 0.5% | 7.0 min | 3 |
| Aug | 182 | 75.8% | 0.5% | 6.4 min | 3 |
| Sep | 153 | 85.0% | 0.0% | 0.0 min | 3 |
| Oct | 140 | 87.1% | 0.0% | -4.0 min | 3 |
| Nov | 110 | 83.6% | 0.0% | -0.8 min | 3 |
| Dec | 69 | 82.6% | 1.4% | -5.4 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from Buffalo (BUF)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| BUF–ORD | Buffalo to Chicago | 2,199 | 72.2% | 16.9 min | 3.2% |
| BUF–MCO | Buffalo to Orlando | 1,792 | 74.4% | 9.7 min | 1.5% |
| BUF–LGA | Buffalo to New York | 1,758 | 74.3% | 9.1 min | 4.8% |
| BUF–BWI | Buffalo to Baltimore | 1,750 | 85.5% | -0.6 min | 1.4% |
| BUF–ATL | Buffalo to Atlanta | 1,520 | 78.1% | 4.2 min | 2.2% |
| BUF–BOS | Buffalo to Boston | 1,295 | 74.1% | 7.9 min | 2.9% |
| BUF–JFK | Buffalo to New York | 1,217 | 72.9% | 10.7 min | 5.6% |
| BUF–DTW | Buffalo to Detroit | 1,207 | 79.5% | 10.0 min | 1.7% |
All 34 routes and the airport record for BUF · airport record for DEN
Questions and answers
How often are flights from Buffalo to Denver on time?
74.7% of the 586 flights scheduled from BUF to DEN in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from BUF to DEN?
Among reporting carriers with at least 60 flights on the route, United Airlines had the highest on-time share (84.3%), followed by Southwest Airlines (65.5%). Differences of a point or two on a few hundred flights are small.
What causes delays between Buffalo and Denver?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 36%, air carrier 36%, national aviation system 26%, extreme weather 3%, security 0%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from BUF?
Flights scheduled to leave BUF from 7 am to 8 am arrived on time 89.5% of the time, the highest of any hour with enough flights to compare. The lowest was 4 pm to 5 pm at 33.8%. Delays tend to build through the day as late aircraft carry over to later flights.
Is it getting better?
The on-time share for the 12 months to July 2026 was 74.7%, down 7.1 points on the previous 12 months (81.8%). The monthly chart on this page shows each of the last 36 months. Across those months, October had the highest on-time share (87.1%) and May the lowest (69.0%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.