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DelayAtlas

Airport month record

BOSJUN

Boston Logan International in June 2026

Departures
12,683
Month
June 2026
National, same month
74.3%
Carriers
10
BGRADE

Historical statistics for June 2026, not live status or a forecast for this year’s June. For today’s conditions at BOS, see live FAA status.

BOS in June lands a B, 2 points better than the national rate of 74.3%. About one flight in four arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 12,683 flights, of which Republic Airways flew 3,121 at 81.4% on time.

Republic Airways is the most reliable of the six carriers covered here at 81.4% on time across 3,121 flights.

Key figures

On time

76.6%

Arrivals under 15 minutes late, of 12,420 completed departures

Avg delay

72 min

Across delayed arrivals only, not all flights

Cancelled

1.77%

Nationally in June: 1.65%

Whole year

75.6%

BOS across all twelve months

These figures cover 12,683 departures from Boston Logan International in June 2026. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

June next to BOS's other months

Against BOS's own year, June ran about a point better than the twelve-month rate of 75.6%, which makes it number five of twelve months, best first.

BOS month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 202512,91270.9%82 min4.07%C−
August 202512,46181.4%69 min1.00%B
September 202511,59775.7%73 min1.35%B
October 202512,64773.9%75 min1.51%C
November 202511,38578.0%75 min2.76%B
December 202511,24868.7%71 min1.69%C
January 202610,29873.6%78 min7.50%C−
February 202610,23274.8%73 min8.15%C−
March 202612,29974.1%69 min2.69%C
April 202612,62679.3%62 min0.31%B+
May 202612,69479.4%60 min0.61%B+
June 2026 (this page)12,68376.6%72 min1.77%B

Departure window

The best time of day to leave BOS in June

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 32 points, against 18 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am2,538 flights90.7%
  • 8am–11am2,663 flights87.0%
  • 11am–2pm1,909 flights78.5%
  • 2pm–5pm2,140 flights71.4%
  • 5pm–8pm2,193 flights60.4%
  • 8pm–5am1,240 flights59.0%

Scale runs 50% to 95%. Rows with fewer than 30 flights show a dash.

The 8pm–5am window is where this operation falls apart: 59.0% on time, against 90.7% 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 2,663 flights scheduled in it.

Across the week, Tuesday is the strongest day at 81.9% on time and Sunday the weakest at 68.4%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week80.8Mon81.9Tue80.7Wed71.1Thu73.2Fri78.3Sat68.4Sun
Monday: 80.8 percent on time. Tuesday: 81.9 percent on time. Wednesday: 80.7 percent on time. Thursday: 71.1 percent on time. Friday: 73.2 percent on time. Saturday: 78.3 percent on time. Sunday: 68.4 percent on time

Carrier by carrier

Which airlines ran best at BOS in June

The choice of carrier is not cosmetic here. Republic Airways arrives on time 81.4% of the time; Southwest Airlines manages 63.5%. Sample sizes sit next to every figure, because a two-point gap across 722 flights means less than a ten-point one.

Carriers at BOS in June 2026
AirlineFlightsOn timeAvg delayCancelledGrade
JetBlue Airways3,15672.4%71 min1.62%C
Republic Airways3,12181.4%71 min2.44%B
Delta Air Lines2,29277.2%69 min1.35%B
American Airlines1,59381.3%91 min2.39%B
United Airlines1,21774.9%79 min1.07%C
Southwest Airlines72263.5%64 min0.69%D+
Alaska Airlinesthin sample24076.6%43 min0.42%B+
Envoy Airthin sample19884.3%81 min3.03%B−
Frontier Airlinesthin sample7775.3%55 min5.19%B−
Allegiant Airthin sample6776.1%83 min0.00%B+

The spread between Republic and Southwest is 18 points, wide enough that it should decide the booking. On a hundred trips that is 18 more arrivals inside the on-time window.

Route by route

Busiest routes out of BOS in June

Routes from BOS in June 2026
RouteFlightsOn timeAvg delayCancelledGrade
BOS to DCA · Washington75774.2%74 min3.43%C−
BOS to ORD · Chicago75076.8%108 min2.80%B
BOS to LGA · New York66181.2%87 min4.39%B−
BOS to SFO · San Francisco50256.5%61 min1.00%D
BOS to ATL · Atlanta46583.0%74 min1.29%B
BOS to PHL · Philadelphia45879.9%89 min2.18%B
BOS to LAX · Los Angeles45268.8%55 min0.66%C+
BOS to JFK · New York43074.0%77 min5.35%C−
BOS to DEN · Denver37471.0%53 min0.27%C+
BOS to CLT · Charlottethin sample35288.2%91 min0.85%A+
BOS to DFW · Dallas-Fort Worththin sample33071.6%76 min5.15%C−
BOS to EWR · Newarkthin sample32777.6%99 min3.06%B−
BOS to BWI · Baltimorethin sample30377.1%72 min0.66%B+
BOS to MCO · Orlandothin sample28573.8%71 min1.05%C
BOS to SEA · Seattlethin sample27874.5%68 min1.08%C
BOS to BNA · Nashvillethin sample26863.5%63 min0.37%D+
BOS to MIA · Miamithin sample26486.7%101 min0.00%A+
BOS to RDU · Raleighthin sample24279.4%86 min3.72%B−
BOS to DTW · Detroitthin sample22171.2%79 min2.26%C
BOS to PIT · Pittsburghthin sample22180.2%75 min4.07%B−
BOS to TPA · Tampathin sample20479.2%66 min0.49%B+
BOS to SAN · San Diegothin sample20366.3%49 min0.49%C+
BOS to IAH · Houstonthin sample18779.1%78 min0.00%B+
BOS to FLL · Fort Lauderdalethin sample17977.6%72 min1.68%B
BOS to IND · Indianapolisthin sample17785.3%59 min0.00%A+

Delay causes

What held BOS up in June

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 210,000 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.

  • Late-arriving aircraft
    44%
  • National Airspace System
    30%
  • Carrier
    25%
  • Extreme weather
    1%
  • Security
    0%

44% 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 210,000 reported delay minutes here, that single category outweighs weather by 29 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 210,168 reported delay minutes.

Cancellations sit at 1.77% against a national 1.65%, which is ordinary. Diversions add another 0.30%.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.5% of arrivals land a full hour or more behind schedule, against 9.7% 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.

What to do with this

Flying from BOS in June

For a June trip through BOS: expect 76.6% on time and 1.77% cancelled, going by June 2026. The 5am–8am window was the strongest part of the day.

Related

Where to go next

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.