BOS → SEA

DL384

DL384 (Delta Air Lines) flies Boston to Seattle. Of 658 departures recorded from October 2024 to July 2026, 87.9% left on time, according to the US BTS.

Recorded departures by month

The most recent periods19 periods
PeriodDepartures 2025Departures 2026Change vs last year
January31310.0%
February28280.0%
March31310.0%
April30300.0%
May31310.0%
June30300.0%
July31310.0%
August31––
September30––
October31–in progress
November30––
December31––
Year to date (Jan–Jul)2122120.0%

according to the US BTS · October 2024 → July 2026

On-time departures by month

All legs combined

On time = departure within 15 minutes of schedule. Non-cancelled flights with a recorded delay only.

The most recent periods19 periods
PeriodOn time 2025On time 2026Change vs last year
January80.7%90.0%▲ 11.6%
February85.7%84.6%▼ 1.3%
March87.1%90.3%▲ 3.7%
April93.3%96.7%▲ 3.6%
May80.7%93.6%▲ 16.0%
June73.3%82.8%▲ 12.9%
July86.2%90.3%▲ 4.8%
August96.8%––
September86.7%––
October93.6%–in progress
November83.3%––
December90.0%––
Year-to-date average (Jan–Jul)83.9%89.7%▲ 7.0%

according to the US BTS · October 2024 → July 2026

Average departure delay by month

All legs combined

according to the US BTS · October 2024 → July 2026

Cancelled departures by month

All legs combined
The most recent periods19 periods
PeriodCancelled 2025Cancelled 2026Change vs last year
January01–
February02–
March00–
April00–
May00–
June01–
July20▼ 100.0%
August0––
September0––
October0–in progress
November0––
December1––
Year to date (Jan–Jul)24▲ 100.0%

according to the US BTS · October 2024 → July 2026

This is not a forecast

This is a historical record of departures already flown, not a forecast for your flight.

Cancellation share

  • Not cancelled 98.9% 651
  • Cancelled 1.1% 7

Share of all recorded flights in the period, all legs. · Oct 12, 2024 → Jul 31, 2026

Legs flown under this number

1
RoutesDistance (km)Avg delay On timeDepartures
BOS SEA Boston Logan International Airport – Seattle–Tacoma International Airport 4,006 4.7 min 87.9% 658
Monthly figures
PeriodDepartures With departure delay recordedOn time Cancelled
October 2024 20 20 85.0% 0
November 2024 30 30 90.0% 0
December 2024 31 31 90.3% 0
January 2025 31 31 80.7% 0
February 2025 28 28 85.7% 0
March 2025 31 31 87.1% 0
April 2025 30 30 93.3% 0
May 2025 31 31 80.7% 0
June 2025 30 30 73.3% 0
July 2025 31 29 86.2% 2
August 2025 31 31 96.8% 0
September 2025 30 30 86.7% 0
October 2025 31 31 93.6% 0
November 2025 30 30 83.3% 0
December 2025 31 30 90.0% 1
January 2026 31 30 90.0% 1
February 2026 28 26 84.6% 2
March 2026 31 31 90.3% 0
April 2026 30 30 96.7% 0
May 2026 31 31 93.6% 0
June 2026 30 29 82.8% 1
July 2026 31 31 90.3% 0

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