Philadelphia (PHL) to Denver (DEN): On-Time Performance
Data through July 2026
The calendar drives reliability on PHL–DEN. October 2024 flights landed on schedule 95% of the time, but December 2025 dropped to 56% — a gap of 39 points. Across the full period the route averages 76% on-time against a national 78%. Morning departures also hold up better than evening ones (85% vs 60%), which matters most in the rough months.
- On-time
- 76%
- arrived <15 min late
- Avg delay
- 19 min
- completed flights
- Cancelled
- 1.3%
- Flights/day
- 8.3
- last 12 months
- Duration
- 4h 15m
- scheduled
- Distance
- 1,558 mi
Best airline from PHL to DEN
4 airlines flew this route regularly between 2024-07 and 2026-07.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 84% | 15 min | 0.7% | 2,005 |
| American Airlines | 73% | 19 min | 2.1% | 1,826 |
| Southwest Airlines | 72% | 18 min | 0.9% | 1,792 |
| Frontier Airlines | 69% | 34 min | 2.3% | 708 |
Monthly on-time trend
Best time to fly from PHL to DEN
Aim for departures around 5 a.m. (90% on-time); avoid 6 p.m. departures (48%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 75% | 23 min |
| Tuesday | 76% | 18 min |
| Wednesdaybest | 78% | 14 min |
| Thursday | 75% | 20 min |
| Friday | 73% | 21 min |
| Saturday | 78% | 17 min |
| Sunday | 75% | 20 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft34%
- Airline operations37%
- National airspace system25%
- Weather4%
Frequently asked questions
- How often are flights from PHL to DEN delayed?
- 24% of PHL–DEN flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-07 and 2026-07. The average arrival delay across completed flights was 19 minutes.
- Which airline is most reliable from PHL to DEN?
- United Airlines has the best on-time record on this route at 84%, based on 2,005 flights. 4 airlines flew PHL–DEN frequently enough to compare in this period.
- What is the best time of day to fly from PHL to DEN?
- Departures around 5 a.m. have the best record (90% on-time), while departures around 6 p.m. have the worst (48%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from PHL to DEN?
- The scheduled PHL–DEN flight time averages 4h 15m over 1,558 miles. Actual arrival times vary — flights on this route land 15+ minutes late 24% of the time.
- How often are PHL to DEN flights cancelled?
- 1.3% of scheduled flights on this route were cancelled between 2024-07 and 2026-07, at or below the national rate of 1.6%.
- What is the worst month to fly from PHL to DEN?
- December 2025 was the roughest month in this dataset, with only 56% of arrivals on time. The best was October 2024 at 95%. If your dates are flexible, that 39-point gap is worth planning around.
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Based on 6,331 flights, 2024-07–2026-07. Source: US DOT Bureau of Transportation Statistics. Updated 2026-09-28.