Flight number record
B6 311
JetBlue Airways · Boston to Chicago
- Route
- BOS → ORD
- Departs
- 07:00
- Flights
- 285
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s B6 311, check with JetBlue Airways.
B6 311 lands a B, 2 points better than the national rate of 77.3%. About one flight in five arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That rests on 285 flights, with a median arrival 8 minutes early.
Key figures
On time
79.1%
Arrivals under 15 minutes late, of 278 completed flights
Avg delay
71 min
Across delayed arrivals only, not all flights
Cancelled
2.11%
National rate is 1.89%
1 hour+ late
7.2%
National rate is 8.3%
These figures cover 285 flights between September 2025 and August 2026. The median arrival is 8 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
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Schedule
When B6 311 flies
B6 311 flies BOS to ORD without a single fixed slot. Its most common scheduled departure was 07:00, used on 70 of 285 flights, with 08:10 (43 flights) and 08:30 (38 flights) next.
- Departs 07:0070 flights24.6%
- Departs 08:1043 flights15.1%
- Departs 08:3038 flights13.3%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and B6 311 runs 10 points worse at 79.1%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.
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Against the route
B6 311 next to BOS to ORD
Every carrier on BOS to ORD combined arrived on time 71.9% of the time across 7,860 flights, so B6 311 is 7 points ahead of it. JetBlue flew 552 flights on the same city pair under all its flight numbers, including this one, and those ran 66.6% on time. Across its whole network JetBlue Airways managed 71.3%, which this flight beats by 8 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| B6 311thin sample | 285 | 79.1% | 71 min | 2.11% | B |
| All JetBlue Airways on BOS–ORD | 552 | 66.6% | 80 min | 3.26% | C− |
| All carriers on BOS–ORD | 7,860 | 71.9% | 87 min | 2.98% | C |
| JetBlue Airways, whole network | 240,615 | 71.3% | 77 min | 3.56% | C− |
Across the year
B6 311 quarter by quarter
B6 311 did not run the same all year. Its best quarter was Apr–Jun 2026 at 87.5% on time and its weakest Jul–Sep 2026 at 67.8%, a swing of 20 points on roughly 57 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights86.7%
- Oct–Dec 202573 flights80.8%
- Jan–Mar 202648 flights72.7%
- Apr–Jun 202672 flights87.5%
- Jul–Sep 202662 flights67.8%
Scale runs 60% to 95%.
By weekday, B6 311 did best on Wednesday at 86.5% on time and worst on Sunday at 73.8%. Each day rests on about 41 flights, so a gap of 13 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late B6 311 runs when it is late
B6 311 often beats the schedule: 100 of 278 completed flights, 36%, arrived 15 minutes or more early. The 58 late arrivals split 16 under half an hour, 22 between 30 and 60 minutes, and 20 an hour or more.
- 15+ min early100 flights36.0%
- Within 15 min120 flights43.2%
- 15–29 min late16 flights5.8%
- 30–59 min late22 flights7.9%
- 1–2 hours late12 flights4.3%
- 2+ hours late8 flights2.9%
Scale runs 0% to 100%.
Share of 278 completed flights by arrival against schedule.
7 of 44 late departures made up the time and arrived on time, 16% of them. In the other direction, 21 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at ORD.
The worst days
Worst days for B6 311
The latest arrival of the period was on 21 July 2026, 6 hours 22 minutes behind schedule; most of its delay minutes were filed as national airspace system delay. The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 21 July 2026 | 6 hours 22 minutes | National Airspace System |
| 14 December 2025 | 5 hours 32 minutes | Carrier |
| 13 September 2025 | 5 hours 20 minutes | National Airspace System |
| 3 August 2026 | 4 hours 50 minutes | Extreme weather |
| 2 August 2026 | 3 hours 38 minutes | National Airspace System |
Delay causes
Why B6 311 runs late
National Airspace System accounts for 49% of the 4,124 delay minutes carriers reported here, and the remaining four split what is left.
- 49%National Airspace System
- 37%Carrier
- 10%Late-arriving aircraft
- 3%Extreme weather
The largest share of delay minutes, 37%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 1,540 of the 4,124 delay minutes reported here. The split is drawn from 4,124 delay minutes reported on B6 311.
Cancellations sit at 2.11% against a national 1.89%, which is ordinary. Diversions add another 0.35%.
Connections and routes
What a delay on this flight costs
7.2% of arrivals land an hour or more late, close to the national 8.3%, so a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.
The 867 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 285 flights under B6 311 in the data flew BOS to ORD. The number was not reused on any other city pair, which makes this a clean record of one route.
One caution: this is a thin sample. 285 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 B6 311
For a booking, read B6 311 as 79.1% on time with 2.11% cancelled over 285 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- BOS to ORD, every carrier and departure
- ORD to BOS, the return direction
- United Airlines 2040 on the same route53.1%
- United Airlines 1414 on the same route93.6%
- United Airlines 1732 on the same route83.8%
- United Airlines 1349 on the same route86.0%
- United Airlines 1015 on the same route50.3%
- Delta Air Lines 2570 on the same route80.5%
- Boston Logan International (BOS) delay statistics
- Chicago O'Hare International (ORD) delay statistics
- JetBlue Airways on-time record
- Every JetBlue Airways flight number with a record
- The most and least reliable flight numbers in the US
- The best time of day to fly, according to 7.05 million flight records
A flight number here means JetBlue Airways’s own number as it reports to the DOT. How the figures are computed is on the methodology page.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.