Denver (DEN) to Boston (BOS): On-Time Performance
Data through May 2026
The calendar drives reliability on DEN–BOS. December 2025 flights landed on schedule 86% of the time, but September 2025 dropped to 51% — a gap of 34 points. Across the full period the route averages 73% on-time against a national 78%.
- On-time
- 73%
- arrived <15 min late
- Avg delay
- 20 min
- completed flights
- Cancelled
- 0.9%
- Flights/day
- 11
- last 12 months
- Duration
- 3h 57m
- scheduled
- Distance
- 1,754 mi
Best airline from DEN to BOS
4 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 77% | 16 min | 0.7% | 3,942 |
| Delta Air Lines | 76% | 15 min | 1.7% | 832 |
| JetBlue Airways | 68% | 30 min | 1.2% | 1,303 |
| Southwest Airlines | 65% | 23 min | 0.6% | 1,781 |
Monthly on-time trend
Best time to fly from DEN to BOS
Aim for departures around 6 a.m. (91% on-time); avoid 6 p.m. departures (53%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 72% | 21 min |
| Tuesday | 74% | 20 min |
| Wednesday | 74% | 17 min |
| Thursday | 69% | 23 min |
| Friday | 70% | 24 min |
| Saturdaybest | 79% | 14 min |
| Sunday | 72% | 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 aircraft38%
- Airline operations25%
- National airspace system36%
- Weather1%
Frequently asked questions
- How often are flights from DEN to BOS delayed?
- 27% of DEN–BOS 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 BOS?
- United Airlines has the best on-time record on this route at 77%, based on 3,942 flights. 4 airlines flew DEN–BOS frequently enough to compare in this period.
- What is the best time of day to fly from DEN to BOS?
- Departures around 6 a.m. have the best record (91% on-time), while departures around 6 p.m. have the worst (53%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from DEN to BOS?
- The scheduled DEN–BOS flight time averages 3h 57m over 1,754 miles. Actual arrival times vary — flights on this route land 15+ minutes late 27% of the time.
- How often are DEN to BOS flights cancelled?
- 0.9% 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 BOS?
- September 2025 was the roughest month in this dataset, with only 51% of arrivals on time. The best was December 2025 at 86%. If your dates are flexible, that 34-point gap is worth planning around.
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Based on 7,858 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.