Carrier route record
B6DEN→BOS
JetBlue Airways · Denver to Boston
- Flights
- 682
- Period
- July 2025 to June 2026
- Share of route
- 17%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with JetBlue Airways.
JetBlue on DEN to BOS sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 682 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,911 at 77.1% on time.
United Airlines is the most reliable of the three carriers covered here at 77.1% on time across 1,911 flights.
Key figures
On time
68.6%
Arrivals under 15 minutes late, of 668 completed flights
Avg delay
82 min
Across delayed arrivals only, not all flights
Cancelled
2.05%
National rate is 1.81%
Whole route
71.4%
Every carrier on DEN to BOS, 3,903 flights
These figures cover 682 flights between July 2025 and June 2026. Beyond the headline rate, 15.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
JetBlue against every carrier on DEN to BOS
JetBlue flew 682 of the 3,903 flights on DEN to BOS, about 17% of it. Its 68.6% on time is 3 points worse than the route as a whole, which runs 71.4%. Ranked by on-time rate it is number three of four carriers on the route, where the range runs from United at 77.1% to Southwest at 59.7%.
The choice of carrier is not cosmetic here. United Airlines arrives on time 77.1% of the time; Southwest Airlines manages 59.7%. Sample sizes sit next to every figure, because a two-point gap across 910 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,911 | 77.1% | 70 min | 0.84% | B+ |
| Delta Air Lines | 400 | 75.8% | 56 min | 1.50% | B |
| JetBlue Airways (this page) | 682 | 68.6% | 82 min | 2.05% | C |
| Southwest Airlines | 910 | 59.7% | 66 min | 1.10% | D |
The spread between United and Southwest is 17 points, wide enough that it should decide the booking. On a hundred trips that is 17 more arrivals inside the on-time window.
Flight by flight
JetBlue flight numbers on DEN to BOS
Departure window
When JetBlue runs best on this route
Departure time is the single lever a traveller controls, and it moves the odds more than most people expect. Each bar below is the on-time rate for flights scheduled to leave inside that window, across 682 flights.
- 5am–8am—
- 8am–11am79 flights64.5%
- 11am–2pm160 flights68.8%
- 2pm–5pm147 flights69.4%
- 5pm–8pm20 flights—
- 8pm–5am276 flights70.2%
Scale runs 55% to 75%. Rows with fewer than 30 flights show a dash.
The overnight block holds up unusually well at 70.2% on time across 276 flights. Red-eyes fly into empty airspace and empty gates, and they are the first rotation of the aircraft's day rather than the last. The 8pm–5am window is the busiest, with 276 flights scheduled in it.
Across the year
JetBlue on DEN to BOS through the year
June is the worst month at 55.3% on time, 24 points below August, the best at 79.3%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 88 flights.
Across the week, Saturday is the strongest day at 76.7% on time and Sunday the weakest at 61.6%. 15 points is a smaller lever than departure hour, but it is free.
Delay causes
Why JetBlue runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 47% of the 17,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 47%Late-arriving aircraft
- 26%National Airspace System
- 26%Carrier
- 0%Extreme weather
47% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 17,000 reported delay minutes here, that single category outweighs weather by 47 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 17,108 reported delay minutes.
Cancellations sit at 2.05% against a national 1.81%, which is ordinary. Diversions add another 0.00%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 15.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
At 1,754 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.
The return leg runs 70.9% on time across 681 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 682 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.
What to do with this
Booking JetBlue on DEN to BOS
Put together: treat all of this as provisional. 682 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 68.6% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 668 completed flights over 12 months sit behind that.
Related
Where to go next
- DEN to BOS, every carrier
- JetBlue on BOS to DEN, the return leg
- United Airlines on DEN to BOS77.1%
- Delta Air Lines on DEN to BOS75.8%
- Southwest Airlines on DEN to BOS59.7%
- JetBlue Airways network-wide record
- Denver International (DEN) delay statistics
- Boston Logan International (BOS) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.