Denver to Boston Flight Delays
Sample size: 10,940 DEN–BOS flights, January 2023 to December 2025 (BTS). 29.58% of Denver to Boston flights arrived at least 15 minutes late. That is 5.4 points worse than the 24.2% median for those routes, so schedule padding matters here. Departure time moves the odds more than anything else on this route: 06:00 departures run 8.77% late against 48.48% for 18:00. Saturday is the calmest day at 25.48%, Friday the worst at 32.91%. Cancellations (2024 to 2025) peak in January at 3.26% of scheduled flights and bottom out in April at 0%. Last updated: 2026-10-01.
These figures are historical US domestic rates, not a forecast for one departure. Use the AI delay predictor before you book.
DEN airport delay guide · BOS airport delay guide · Predict a DEN to BOS flight
Best time to fly DEN to BOS
The best time to fly DEN to BOS is the 6 AM departure and fly on a Saturday, not a Friday (25.48% against 32.91%): 8.77% of 6 AM flights arrived 15+ minutes late, against 48.48% at 6 PM.
Lowest observed delay rates depart 06:00–08:00. The highest sit at 14:00, 18:00–19:00. Only departure hours with at least 100 recorded flights are listed, so sparse hours are blank rather than estimated.
| Departure hour | Delayed 15+ min | Flights observed |
|---|---|---|
| 06:00 | 8.77% | 114 |
| 07:00 | 11.59% | 328 |
| 08:00 | 15.93% | 929 |
| 09:00 | 25.91% | 1,185 |
| 10:00 | 30.23% | 311 |
| 11:00 | 30.78% | 1,530 |
| 12:00 | 37.29% | 354 |
| 13:00 | 33.28% | 1,160 |
| 14:00 | 43.37% | 332 |
| 15:00 | 39.1% | 312 |
| 16:00 | 33.33% | 591 |
| 17:00 | 35.29% | 1,417 |
| 18:00 | 48.48% | 330 |
| 19:00 | 40.56% | 249 |
| 22:00 | 32.8% | 186 |
| 23:00 | 22.02% | 1,558 |
DEN to BOS flight time and distance
Scheduled gate-to-gate time from DEN to BOS is a median 3 h 56 min. Flights actually took a median 3 h 48 min gate to gate, including 3 h 23 min in the air. 2.5% ran 30 or more minutes over schedule and 70.3% arrived sooner than scheduled (BTS data, January 2023 to December 2025).
DEN to BOS is 1,754 miles (BTS data).
| Airline | Scheduled (median) | Actual (median) | In the air (median) | 30+ min over schedule | Flights |
|---|---|---|---|---|---|
| United Airlines | 3 h 58 min | 3 h 49 min | 3 h 23 min | 2.5% | 5,653 |
| Southwest Airlines | 3 h 50 min | 3 h 44 min | 3 h 22 min | 2.0% | 2,303 |
| JetBlue Airways | 3 h 52 min | 3 h 47 min | 3 h 23 min | 3.5% | 1,754 |
| Delta Air Lines | 4 h 2 min | 3 h 53 min | 3 h 22 min | 2.0% | 1,230 |
How late, and why
When a DEN to BOS flight was late (15+ minutes), it arrived an average of 68 minutes late (median 45). 11.3% of all completed flights arrived an hour or more late (BTS data, 2023 to 2025).
Of the delay minutes on late DEN to BOS flights, 37.6% were caused by a late incoming aircraft, 30.4% by the air-traffic system (volume, non-extreme weather, airport operations), 29.7% by the airline (crew, maintenance, ground handling), 2.1% by extreme weather and 0.2% by security (BTS data, 2023 to 2025).
| Cause | Share of delay minutes |
|---|---|
| late incoming aircraft | 37.6% |
| air-traffic system | 30.4% |
| airline | 29.7% |
| extreme weather | 2.1% |
| security | 0.2% |
BTS assigns causes to delay minutes on flights that arrived 15+ minutes late. "Air-traffic system" includes non-extreme weather that slows traffic.
DEN to BOS delays by day of week
| Day | Delayed 15+ min | Flights observed |
|---|---|---|
| Mon | 31.7% | 1,637 |
| Tue | 28.42% | 1,492 |
| Wed | 26.26% | 1,550 |
| Thu | 32.69% | 1,609 |
| Fri | 32.91% | 1,641 |
| Sat | 25.48% | 1,401 |
| Sun | 28.76% | 1,610 |
Month-by-month cancellation pattern
Share of scheduled DEN–BOS flights cancelled in each month, from BTS 2024–2025 on-time reporting. These are cancellations, not delays. Delay figures on this page cover January 2023 to December 2025.
| Month | Cancelled | Flights scheduled |
|---|---|---|
| Jan | 3.26% | 522 |
| Feb | 0.85% | 473 |
| Mar | 0.53% | 564 |
| Apr | 0% | 544 |
| May | 0.46% | 647 |
| Jun | 0.13% | 750 |
| Jul | 2.33% | 815 |
| Aug | 0.62% | 808 |
| Sep | 0.44% | 687 |
| Oct | 0% | 705 |
| Nov | 0.17% | 602 |
| Dec | 0.66% | 607 |
Airlines on DEN to BOS: delays and cancellations
United Airlines, Southwest Airlines, JetBlue Airways and Delta Air Lines fly this route today. Only carriers with at least 200 scheduled flights on the pairing are listed. Delay rates cover January 2023 to December 2025; cancellation rates cover 2024 to 2025.
| Airline | Share of flights | Delayed 15+ min | Cancelled | Flights scheduled |
|---|---|---|---|---|
| United Airlines | 51% | 24.38% | 0.84% | 3,907 |
| Southwest Airlines | 23% | 39.69% | 0.34% | 1,758 |
| JetBlue Airways | 16% | 35.8% | 0.82% | 1,226 |
| Delta Air Lines | 11% | 25.69% | 1.32% | 833 |
Related pages
- DEN delays: rate, worst hours and live risk
- BOS delays: rate, worst hours and live risk
- Boston to DC flights (BOS to DCA)
- DC to Boston flights (DCA to BOS)
- US airline cancellation rates
- Thanksgiving and Christmas 2026 flight delay guide
- Predict a DEN to BOS flight
Check your odds: Will my flight be delayed? · Will my flight be cancelled?
DEN vs BOS: airport conditions
Both ends of a route shape its delay profile. These are DelayGuard's operational scores for Denver and Boston.
| Measure | DEN (Denver) | BOS (Boston) |
|---|---|---|
| Congestion | high | high |
| Weather risk | moderate | moderate |
| NAS vulnerability | moderate | high |
| Average taxi-out | 17 min | 16 min |
| Runways | 6 | 6 |
DEN to BOS questions
- How long is the flight from Denver to Boston?
- Scheduled gate-to-gate time from DEN to BOS is a median 3 h 56 min, and flights actually took a median 3 h 48 min including 3 h 23 min in the air. 2.5% ran 30+ minutes over schedule (BTS data, January 2023 to December 2025).
- How often do DEN to BOS flights get delayed?
- Across 10,940 recorded DEN–BOS departures, January 2023 to December 2025 (BTS), 29.58% arrived at least 15 minutes late. Departure time matters most: 6:00 departures run 8.77% late against 48.48% for 18:00. Actual delay frequency varies by airline, time of day, and season.
- What is the best time of year to fly DEN to BOS?
- Both Denver and Boston share the same primary risk window: December–February (winter weather) and June–August (summer storms). Plan around those periods for the lowest delay probability on this route.
- Which airline is most reliable on DEN to BOS?
- On DEN→BOS, United Airlines has the lowest measured delay rate at 24.38% of 5,653 flights, and Southwest Airlines the highest at 39.69% (BTS, January 2023 to December 2025). Southwest Airlines cancels the fewest at 0.34% (2024 to 2025). These are route-specific figures, not airline-wide averages.
- How late are DEN to BOS flights when they are delayed?
- When a DEN to BOS flight was late (15+ minutes), it arrived an average of 68 minutes late (median 45). 11.3% of all completed flights arrived an hour or more late (BTS data, 2023 to 2025).
- How accurate is DelayGuard's delay prediction for this route?
- DelayGuard's delay risk score comes from an ML model trained on BTS data (3.95 million US domestic flights, 2023 to mid-2025), with live weather data (within 5 days of departure) and FAA NAS advisories (within 6 hours) — a likelihood of delay, not a guarantee.
Delay figures reflect arrivals 15 or more minutes late in BTS on-time reporting. Cancellation figures are separate and count flights that never operated. Hours, days and months with fewer than 100 recorded flights are omitted rather than estimated.