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Route on-time record

BOS to BWI: most on-time flights and the best time to fly

Boston (Boston Logan International Airport) to Baltimore (Baltimore/Washington International Thurgood Marshall Airport). 3,605 nonstop flights in Jun 2025 to May 2026, 78% arrived within 15 minutes and 2.7% were cancelled. The most reliable flight number was Southwest 4210 at 5:30 AM.

Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.

BOS → BWI

Boston to Baltimore: 3,605 nonstop flights a year

On time (12 months)

78%

Cancelled

2.7%

avg delay 17 min

Best time to leave

Before 9 AM

92% on time vs 46% after 9 PM

Most reliable airline

Republic

79% chance on time

Check BOS to BWI fares

Lowest nonstop fare seen in the next two months: $55 (Southwest 792 on 2026-11-24). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.

Most reliable nonstop flights

Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.

  1. #1 · Southwest 4210

    5:30 AM → 7:05 AM1h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1172, 1245; its record covers all of them.

    92%

    chance on time

    On time (history)
    95%
    Cancelled
    0.0%
    Avg arrival delay
    3 min
    • Arrived on time 95% of the time (88 flights, Jun 2025 to May 2026).
    • Never cancelled in 88 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Moderate track record · 88 flights

    Find Southwest 4210 fares Opens this date on Aviasales

  2. #2 · Southwest 874

    7:20 AM → 9:05 AM1h 45m nonstop

    Local times, typical schedule. Last flown 2026-05-29.

    90%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (23 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (23 flights), so its score leans on the airline's record at this hour.

    Limited track record · 23 flights

    Find Southwest 874 fares Opens this date on Aviasales

  3. #3 · Southwest 1250

    9:00 AM → 10:40 AM1h 40m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    89%

    chance on time

    On time (history)
    94%
    Cancelled
    0.0%
    Avg arrival delay
    2 min
    • Arrived on time 94% of the time (33 flights, Jun 2025 to May 2026).
    • Never cancelled in 33 scheduled flights.
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (33 flights), so its score leans on the airline's record at this hour.

    Limited track record · 33 flights

    Find Southwest 1250 fares Opens this date on Aviasales

  4. #4 · Southwest 261

    6:20 AM → 8:00 AM1h 40m nonstop

    Local times, typical schedule. Last flown 2026-05-27.

    88%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (16 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (16 flights), so its score leans on the airline's record at this hour.

    Limited track record · 16 flights

    Find Southwest 261 fares Opens this date on Aviasales

  5. #5 · Southwest 237

    7:00 AM → 8:40 AM1h 40m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    88%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    2 min
    • Arrived on time 100% of the time (15 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (15 flights), so its score leans on the airline's record at this hour.

    Limited track record · 15 flights

    Find Southwest 237 fares Opens this date on Aviasales

  6. #6 · Southwest 4552

    9:10 AM → 10:45 AM1h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    88%

    chance on time

    On time (history)
    94%
    Cancelled
    0.0%
    Avg arrival delay
    2 min
    • Arrived on time 94% of the time (16 flights, Jun 2025 to May 2026).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (16 flights), so its score leans on the airline's record at this hour.

    Limited track record · 16 flights

    Find Southwest 4552 fares Opens this date on Aviasales

  7. #7 · Southwest 2529

    8:45 AM → 10:25 AM1h 40m nonstop

    Local times, typical schedule. Last flown 2026-05-29.

    88%

    chance on time

    On time (history)
    95%
    Cancelled
    0.0%
    Avg arrival delay
    3 min
    • Arrived on time 95% of the time (39 flights, Jun 2025 to May 2026).
    • Never cancelled in 39 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Limited track record · 39 flights

    Find Southwest 2529 fares Opens this date on Aviasales

  8. #8 · Southwest 786

    6:40 AM → 8:15 AM1h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    87%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (8 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (8 flights), so its score leans on the airline's record at this hour.

    Limited track record · 8 flights

    Find Southwest 786 fares Opens this date on Aviasales

  9. #9 · Southwest 4183

    11:40 AM → 1:15 PM1h 35m nonstop

    Local times, typical schedule. Last flown 2026-05-27.

    85%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    1 min
    • Arrived on time 100% of the time (16 flights, Jun 2025 to May 2026).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).
    • Short track record (16 flights), so its score leans on the airline's record at this hour.

    Limited track record · 16 flights

    Find Southwest 4183 fares Opens this date on Aviasales

  10. #10 · Republic 5703 · sold as American Eagle, Delta Connection or United Express

    8:28 AM → 10:13 AM1h 45m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    84%

    chance on time

    On time (history)
    89%
    Cancelled
    3.0%
    Avg arrival delay
    8 min
    • Arrived on time 89% of the time (158 flights, Jun 2025 to May 2026).
    • Cancelled 3.0% of the time (5 of 164).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 46%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Moderate track record · 158 flights

    Find 8:28 AM flight fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Republic Airways (sold as American Eagle, Delta Connection or United Express)79%

    1,083 flights · 82% on time as flown · 3.2% cancel

  • Southwest Airlines75%

    2,376 flights · 77% on time as flown · 2.4% cancel

  • Spirit Airlines70%

    146 flights · 66% on time as flown · 3.8% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM92%

    1,066 flights · avg delay 5 min

  • 9 AM to noon89%

    493 flights · avg delay 6 min

  • Noon to 3 PM84%

    692 flights · avg delay 11 min

  • 3 to 6 PM69%

    712 flights · avg delay 25 min

  • 6 to 9 PM50%

    489 flights · avg delay 42 min

  • After 9 PM46%

    153 flights · avg delay 41 min

Best day: Tuesday (85%). Worst: Sunday (76%).

Smarter routing

Nearby airports that run more on time

  • MHT → BWI 86% chance on time

    Manchester-Boston Regional Airport to Baltimore/Washington International Thurgood Marshall Airport · 1,710 flights a year · 45 mi from your airports · yours: 76%

    Rank flightsFares

  • PVD → BWI 82% chance on time

    Rhode Island T. F. Green International Airport to Baltimore/Washington International Thurgood Marshall Airport · 1,885 flights a year · 49 mi from your airports · yours: 76%

    Rank flightsFares

  • BOS → IAD 81% chance on time

    Boston Logan International Airport to Washington Dulles International Airport · 1,490 flights a year · 45 mi from your airports · yours: 76%

    Rank flightsFares

On time by month

All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.

J
86
F
85
M
85
A
82
M
77
J
74
J
69
A
76
S
78
O
80
N
87
D
84

What delays this route

  • Late-arriving aircraft53%
  • Airline (crew, maintenance, boarding)25%
  • Air traffic control and airport volume19%
  • Severe weather4%

Share of delay minutes by the cause airlines report to the US DOT.

Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure

BOS to BWI questions

What time of day is best to fly BOS to BWI?
Before 9 AM: 92% of flights arrived on time, against 46% for departures after 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
Which airline is most on time from BOS to BWI?
Republic, with a season-adjusted 79% chance of operating and arriving on time over 1,083 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
What is the worst month for delays on BOS to BWI?
July (69% on time); the best was November (87%), averaged over Jun 2023 to May 2026.
Is this a prediction for my flight?
No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.

More routes from BOS

Live status: FAA delays and ground stops