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DelayAtlas

Flight number record

B6 1734

JetBlue Airways · San Francisco to Boston

Route
SFO → BOS
Departs
10:25
Flights
342
Period
September 2025 to August 2026
C−GRADE

Historical statistics for September 2025 to August 2026, not live status. For today’s B6 1734, check with JetBlue Airways.

B6 1734 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 342 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.3%, so B6 1734 runs 11 points behind the country as a whole. Across a thousand flights that is about 111 extra late arrivals.

Key figures

On time

66.2%

Arrivals under 15 minutes late, of 331 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

3.22%

National rate is 1.89%

1 hour+ late

13.0%

National rate is 8.3%

These figures cover 342 flights between September 2025 and August 2026. Beyond the headline rate, 13.0% 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.

Schedule

When B6 1734 flies

B6 1734 flies SFO to BOS without a single fixed slot. Its most common scheduled departure was 10:25, used on 81 of 342 flights, with 12:20 (45 flights) next.

  • Departs 10:2581 flights23.7%
  • Departs 12:2045 flights13.2%

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 10:25 departure sits in the 8am–11am window. Across every US flight scheduled in that window the on-time rate is 83.9%, and B6 1734 runs 18 points worse at 66.2%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

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.

Against the route

B6 1734 next to SFO to BOS

Every carrier on SFO to BOS combined arrived on time 74.5% of the time across 4,815 flights, so B6 1734 is 8 points behind it. JetBlue flew 1,806 flights on the same city pair under all its flight numbers, including this one, and those ran 71.5% on time. Across its whole network JetBlue Airways managed 71.3%, which this flight trails by 5 points.

B6 1734 against its route and carrier
Compared withFlightsOn timeAvg delayCancelledGrade
B6 1734thin sample34266.2%63 min3.22%C−
All JetBlue Airways on SFO–BOS1,80671.5%78 min2.77%C
All carriers on SFO–BOS4,81574.5%74 min1.81%C
JetBlue Airways, whole network240,61571.3%77 min3.56%C−

Across the year

B6 1734 quarter by quarter

B6 1734 did not run the same all year. Its best quarter was Jan–Mar 2026 at 77.6% on time and its weakest Apr–Jun 2026 at 53.6%, a swing of 24 points on roughly 68 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 flights63.3%
  • Oct–Dec 202591 flights69.0%
  • Jan–Mar 202690 flights77.6%
  • Apr–Jun 202669 flights53.6%
  • Jul–Sep 202662 flights61.7%

Scale runs 45% to 85%.

By weekday, B6 1734 did best on Saturday at 79.2% on time and worst on Thursday at 47.9%. Each day rests on about 49 flights, so a gap of 31 points is worth noticing but could still narrow in another year.

On-time rate by day of the week53.2Mon63.8Tue78.7Wed47.9Thu74.5Fri79.2Sat66.0Sun
Monday: 53.2 percent on time. Tuesday: 63.8 percent on time. Wednesday: 78.7 percent on time. Thursday: 47.9 percent on time. Friday: 74.5 percent on time. Saturday: 79.2 percent on time. Sunday: 66.0 percent on time

Arrival by arrival

How late B6 1734 runs when it is late

B6 1734 often beats the schedule: 112 of 331 completed flights, 34%, arrived 15 minutes or more early. The 112 late arrivals split 30 under half an hour, 39 between 30 and 60 minutes, and 43 an hour or more.

  • 15+ min early112 flights33.8%
  • Within 15 min107 flights32.3%
  • 15–29 min late30 flights9.1%
  • 30–59 min late39 flights11.8%
  • 1–2 hours late27 flights8.2%
  • 2+ hours late16 flights4.8%

Scale runs 0% to 100%.

Share of 331 completed flights by arrival against schedule.

14 of 103 late departures made up the time and arrived on time, 14% of them. In the other direction, 23 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 BOS.

The worst days

Worst days for B6 1734

The latest arrival of the period was on 21 December 2025, 3 hours 19 minutes behind schedule; most of its delay minutes were filed as a late-arriving aircraft. On three of the five worst days the largest share was filed as national airspace system delay.

The latest arrivals of B6 1734 in the period
DateArrived late byLargest filed cause
21 December 20253 hours 19 minutesLate-arriving aircraft
13 October 20253 hours 18 minutesNational Airspace System
1 March 20263 hours 5 minutesLate-arriving aircraft
1 July 20263 hours 1 minuteNational Airspace System
6 November 20252 hours 58 minutesNational Airspace System

Delay causes

Why B6 1734 runs late

National Airspace System accounts for 62% of the 7,028 delay minutes carriers reported here, and the remaining four split what is left.

  • National Airspace System
    62%
  • Late-arriving aircraft
    28%
  • Carrier
    10%

62% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 4,374 minutes out of 7,028, against a national NAS share of 21%. The split is drawn from 7,028 delay minutes reported on B6 1734.

Cancellations run at 3.22%, against 1.89% nationally. That is about one flight in 30 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 routes

What a delay on this flight costs

13.0% 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.

At 2,704 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.

Every one of the 342 flights under B6 1734 in the data flew SFO to BOS. 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. 342 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 1734

For a booking, the cancellation rate is the figure to plan around on B6 1734: 3.22% of its 342 scheduled flights did not operate. A late arrival costs about an hour, but a cancellation costs the day, so leave a later option open.

Related

Where to go next

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.