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Route on-time record

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

Boston (Boston Logan International Airport) to Denver (Denver International Airport). 3,909 nonstop flights in Jun 2025 to May 2026, 76% arrived within 15 minutes and 1.2% were cancelled. The most reliable flight number was United 662 at 9:15 AM.

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

BOS → DEN

Boston to Denver: 3,909 nonstop flights a year

On time (12 months)

76%

Cancelled

1.2%

avg delay 15 min

Best time to leave

Before 9 AM

88% on time vs 53% 6 to 9 PM

Most reliable airline

United

81% chance on time

Check BOS to DEN fares

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 · United 662

    9:15 AM → 12:02 PM4h 47m nonstop

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

    90%

    chance on time

    On time (history)
    92%
    Cancelled
    1.1%
    Avg arrival delay
    7 min
    • Arrived on time 92% of the time (275 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).

    Strong track record · 275 flights

    Find United 662 fares Opens this date on Aviasales

  2. #2 · United 647

    7:09 AM → 10:00 AM4h 51m nonstop

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

    89%

    chance on time

    On time (history)
    91%
    Cancelled
    1.6%
    Avg arrival delay
    5 min
    • Arrived on time 91% of the time (358 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 88% on time; 6 to 9 PM: 53%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Strong track record · 358 flights

    Find United 647 fares Opens this date on Aviasales

  3. #3 · United 414

    11:15 AM → 2:03 PM4h 48m nonstop

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

    88%

    chance on time

    On time (history)
    89%
    Cancelled
    1.1%
    Avg arrival delay
    6 min
    • Arrived on time 89% of the time (360 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).
    • Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.

    Strong track record · 360 flights

    Find United 414 fares Opens this date on Aviasales

  4. #4 · JetBlue 493

    10:45 AM → 1:25 PM4h 40m nonstop

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

    84%

    chance on time

    On time (history)
    88%
    Cancelled
    2.6%
    Avg arrival delay
    4 min
    • Arrived on time 88% of the time (74 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).

    Moderate track record · 74 flights

    Find JetBlue 493 fares Opens this date on Aviasales

  5. #5 · United 2297

    3:05 PM → 5:53 PM4h 48m nonstop

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

    84%

    chance on time

    On time (history)
    85%
    Cancelled
    0.9%
    Avg arrival delay
    12 min
    • Arrived on time 85% of the time (333 flights, Jun 2025 to May 2026).
    • Departs inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
    • Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.

    Strong track record · 333 flights

    Find United 2297 fares Opens this date on Aviasales

  6. #6 · Delta 499

    7:30 AM → 10:24 AM4h 50m nonstop

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

    83%

    chance on time

    On time (history)
    84%
    Cancelled
    1.6%
    Avg arrival delay
    9 min
    • Arrived on time 84% of the time (359 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 88% on time; 6 to 9 PM: 53%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Strong track record · 359 flights

    Find Delta 499 fares Opens this date on Aviasales

  7. #7 · Southwest 3705

    5:15 AM → 7:45 AM4h 30m nonstop

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

    81%

    chance on time

    On time (history)
    89%
    Cancelled
    0.0%
    Avg arrival delay
    3 min
    • Arrived on time 89% of the time (55 flights, Jun 2025 to May 2026).
    • Never cancelled in 55 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 88% on time; 6 to 9 PM: 53%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Limited track record · 55 flights

    Find Southwest 3705 fares Opens this date on Aviasales

  8. #8 · Southwest 1257

    5:00 AM → 7:45 AM4h 45m nonstop

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

    80%

    chance on time

    On time (history)
    88%
    Cancelled
    0.0%
    Avg arrival delay
    11 min
    • Arrived on time 88% of the time (33 flights, Jun 2025 to May 2026).
    • Never cancelled in 33 scheduled flights.
    • Leaves in this route's most on-time window (Before 9 AM: 88% on time; 6 to 9 PM: 53%).
    • Departs outside BOS's trouble window (noon to 6 PM, when 79% of its 196 ground stops and delay programs started).

    Limited track record · 33 flights

    Find Southwest 1257 fares Opens this date on Aviasales

  9. #9 · JetBlue 393

    10:55 AM → 12:40 PM4h 44m nonstop

    Local times, typical schedule. Last flown 2026-05-20.

    79%

    chance on time

    On time (history)
    81%
    Cancelled
    1.6%
    Avg arrival delay
    12 min
    • Arrived on time 81% of the time (314 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).

    Strong track record · 314 flights

    Find JetBlue 393 fares Opens this date on Aviasales

  10. #10 · United 800

    4:50 PM → 7:40 PM4h 48m nonstop

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

    71%

    chance on time

    On time (history)
    73%
    Cancelled
    1.2%
    Avg arrival delay
    19 min
    • Arrived on time 73% of the time (247 flights, Jun 2025 to May 2026).
    • Departs inside BOS's trouble window: 79% of its 196 ground stops and delay programs started between noon and 6 PM.
    • Lands inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.

    Strong track record · 247 flights

    Find United 800 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • United Airlines81%

    1,913 flights · 82% on time as flown · 1.1% cancel

  • Delta Air Lines78%

    415 flights · 79% on time as flown · 1.6% cancel

  • JetBlue72%

    674 flights · 72% on time as flown · 1.5% cancel

  • Southwest Airlines66%

    907 flights · 66% on time as flown · 0.9% cancel

On time by departure time

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

  • Before 9 AM88%

    1,160 flights · avg delay 6 min

  • 9 AM to noon87%

    963 flights · avg delay 8 min

  • Noon to 3 PM74%

    244 flights · avg delay 13 min

  • 3 to 6 PM66%

    944 flights · avg delay 23 min

  • 6 to 9 PM53%

    598 flights · avg delay 31 min

Best day: Wednesday (81%). Worst: Friday (75%).

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
79
F
77
M
84
A
78
M
78
J
73
J
68
A
74
S
81
O
83
N
86
D
84

What delays this route

  • Late-arriving aircraft44%
  • Air traffic control and airport volume28%
  • Airline (crew, maintenance, boarding)25%
  • Severe weather3%

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 DEN questions

What time of day is best to fly BOS to DEN?
Before 9 AM: 88% of flights arrived on time, against 53% for departures 6 to 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 DEN?
United, with a season-adjusted 81% chance of operating and arriving on time over 1,913 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 DEN?
July (68% on time); the best was November (86%), 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