Carrier route record

B6ORD→BOS

JetBlue Airways · Chicago to Boston

Flights: 553
Period: September 2025 to August 2026
Share of route: 7%
Carriers: 6

Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with JetBlue Airways.

JetBlue on ORD 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 77.3%. The late ones land an hour and a half behind schedule. That rests on 553 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 440 at 82.7% on time.

Envoy Air is the most reliable of the five carriers covered here at 82.7% on time across 440 flights.

On time

68.1%

Arrivals under 15 minutes late, of 529 completed flights

Avg delay

98 min

Across delayed arrivals only, not all flights

Cancelled

3.98%

National rate is 1.89%

Whole route

66.6%

Every carrier on ORD to BOS, 7,864 flights

These figures cover 553 flights between September 2025 and August 2026. Beyond the headline rate, 15.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.

Fare search by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Carrier by carrier

JetBlue against every carrier on ORD to BOS

JetBlue flew 553 of the 7,864 flights on ORD to BOS, about 7% of it. Its 68.1% on time is 2 points better than the route as a whole, which runs 66.6%. Ranked by on-time rate it is number three of six carriers on the route, where the range runs from Envoy at 82.7% to American at 59.5%.

The choice of carrier is not cosmetic here. Envoy Air arrives on time 82.7% of the time; American Airlines manages 59.5%. Sample sizes sit next to every figure, because a two-point gap across 2,164 flights means less than a ten-point one.

On-time performance by carrier on ORD to BOS
Airline	Flights	On time	Avg delay	Cancelled	Grade
Envoy Air	440	82.7%	67 min	2.50%	B
Republic Airways	932	69.7%	79 min	5.90%	C−
JetBlue Airways (this page)	553	68.1%	98 min	3.98%	C−
United Airlines	2,794	68.0%	80 min	1.79%	C
Delta Air Lines	981	67.4%	90 min	3.47%	C−
American Airlines	2,164	59.5%	78 min	2.91%	D

Republic Airways cancels 5.9% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Flight by flight

JetBlue flight numbers on ORD to BOS

B6 31210:5669.5% · 335 flights

Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.

Departure window

When JetBlue runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 26 points, against 23 points between the best and worst carrier.

5am–8am61 flights81.4%
8am–11am151 flights79.7%
11am–2pm137 flights59.0%
2pm–5pm14 flights—
5pm–8pm70 flights71.2%
8pm–5am120 flights55.6%

Scale runs 45% to 85%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 55.6% on time, against 81.4% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8am–11am window is the busiest, with 151 flights scheduled in it.

Across the year

JetBlue on ORD to BOS through the year

Darker means more delays. Figures are on-time percentages.May best, August worst

August is the worst month at 45.3% on time, 45 points below May, the best at 90.0%. 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 58 flights.

Across the week, Wednesday is the strongest day at 77.1% on time and Monday the weakest at 61.4%, a spread of 16 points.

Arrival by arrival

How late JetBlue on ORD to BOS runs when it is late

JetBlue on ORD to BOS often beats the schedule: 169 of 529 completed flights, 32%, arrived 15 minutes or more early. The 169 late arrivals split 39 under half an hour, 49 between 30 and 60 minutes, and 81 an hour or more.

15+ min early169 flights31.9%
Within 15 min191 flights36.1%
15–29 min late39 flights7.4%
30–59 min late49 flights9.3%
1–2 hours late41 flights7.8%
2+ hours late40 flights7.6%

Scale runs 0% to 100%.

Share of 529 completed flights by arrival against schedule.

21 of 164 late departures made up the time and arrived on time, 13% of them. 26 flights left on time and still arrived late.

The worst days

Worst days for JetBlue on ORD to BOS

The latest arrival of the period was on 27 July 2026, 26 hours 34 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.

The latest arrivals of JetBlue on ORD to BOS in the period
Date	Arrived late by	Largest filed cause
27 July 2026	26 hours 34 minutes	Carrier
16 October 2025	16 hours 29 minutes	Carrier
6 March 2026	9 hours 24 minutes	Late-arriving aircraft
21 July 2026	6 hours 5 minutes	Late-arriving aircraft
14 December 2025	5 hours 35 minutes	Late-arriving aircraft

Delay causes

Why JetBlue runs late on this route

Late-arriving aircraft accounts for 52% of the 17,000 delay minutes carriers reported here, and the remaining four split what is left.

Late-arriving aircraft
52%
Carrier
29%
National Airspace System
19%
Extreme weather
0%

52% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 17,000 reported delay minutes here, that single category outweighs weather by 52 to one. The split is drawn from 16,503 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 81.4% on time here.

Cancellations run at 3.98%, against 1.89% nationally. That is about one flight in 25 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.

Connections and stage length

What a delay here costs

15.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.

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.

The return leg runs 66.6% on time across 552 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. 553 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 ORD to BOS

Put together: the delay figures matter less here than the 3.98% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 529 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures