Denver (DEN) to Philadelphia (PHL): On-Time Performance
Data through May 2026
When you fly DEN to PHL matters as much as anything else about the booking: the route swung from 86% on-time in October 2024 to just 59% in June 2025. Across the full period the route averages 74% on-time against a national 78%. Morning departures also hold up better than evening ones (83% vs 67%), which matters most in the rough months.
- On-time
- 74%
- arrived <15 min late
- Avg delay
- 20 min
- completed flights
- Cancelled
- 1.2%
- Flights/day
- 8.2
- last 12 months
- Duration
- 3h 36m
- scheduled
- Distance
- 1,558 mi
Best airline from DEN to PHL
4 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 80% | 13 min | 0.5% | 1,922 |
| American Airlines | 77% | 23 min | 2.2% | 1,689 |
| Southwest Airlines | 68% | 20 min | 0.6% | 1,679 |
| Frontier Airlines | 60% | 36 min | 2.1% | 676 |
Monthly on-time trend
Best time to fly from DEN to PHL
Aim for departures around 7 a.m. (88% on-time); avoid 7 p.m. departures (47%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 71% | 28 min |
| Tuesdaybest | 79% | 15 min |
| Wednesday | 73% | 17 min |
| Thursday | 72% | 20 min |
| Friday | 74% | 22 min |
| Saturday | 77% | 18 min |
| Sunday | 70% | 22 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft43%
- Airline operations39%
- National airspace system17%
- Weather1%
Frequently asked questions
- How often are flights from DEN to PHL delayed?
- 27% of DEN–PHL 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 20 minutes.
- Which airline is most reliable from DEN to PHL?
- United Airlines has the best on-time record on this route at 80%, based on 1,922 flights. 4 airlines flew DEN–PHL frequently enough to compare in this period.
- What is the best time of day to fly from DEN to PHL?
- Departures around 7 a.m. have the best record (88% on-time), while departures around 7 p.m. have the worst (47%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DEN to PHL?
- The scheduled DEN–PHL flight time averages 3h 36m over 1,558 miles. Actual arrival times vary — flights on this route land 15+ minutes late 27% of the time.
- How often are DEN to PHL flights cancelled?
- 1.2% 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 PHL?
- June 2025 was the roughest month in this dataset, with only 59% of arrivals on time. The best was October 2024 at 86%. If your dates are flexible, that 27-point gap is worth planning around.
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Based on 5,966 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.