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DelayAtlas

Airport month record

SEAOCT

Seattle-Tacoma International in October 2025

Departures
13,859
Month
October 2025
National, same month
79.7%
Carriers
10
BGRADE

Historical statistics for October 2025, not live status or a forecast for this year’s October. For today’s conditions at SEA, see live FAA status.

SEA in October lands a B, 3 points better than the national rate of 79.7%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 13,859 flights, of which SkyWest Airlines flew 2,532 at 89.5% on time.

SkyWest Airlines is the most reliable of the six carriers covered here at 89.5% on time across 2,532 flights.

Key figures

On time

82.9%

Arrivals under 15 minutes late, of 13,674 completed departures

Avg delay

58 min

Across delayed arrivals only, not all flights

Cancelled

1.16%

Nationally in October: 0.53%

Whole year

79.4%

SEA across all twelve months

These figures cover 13,859 departures from Seattle-Tacoma International in October 2025. 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

October next to SEA's other months

Against SEA's own year, October ran 4 points better than the twelve-month rate of 79.4%, which makes it number four of twelve months, best first. Either side of it, September ran 82.9% on time and November 81.9%, so this month sits in line with its neighbours.

SEA month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 202516,57769.2%57 min1.38%C
August 202515,97073.6%51 min0.66%C+
September 202514,55282.9%50 min0.29%B+
October 2025 (this page)13,85982.9%58 min1.16%B
November 202512,61681.9%58 min1.69%B
December 202513,02374.0%59 min1.02%C
January 202611,92781.6%60 min1.91%B
February 202611,00084.4%56 min0.78%B+
March 202612,83080.2%64 min2.23%B
April 202612,86485.6%56 min0.17%A+
May 202614,56482.2%52 min0.41%B+
June 202615,40278.1%57 min0.48%B+

Departure window

The best time of day to leave SEA in October

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 points, against 15 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,551 flights91.5%
  • 8am–11am3,108 flights83.4%
  • 11am–2pm2,586 flights80.7%
  • 2pm–5pm2,159 flights80.8%
  • 5pm–8pm2,074 flights78.1%
  • 8pm–5am2,381 flights85.0%

Scale runs 70% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.5% of the time, against 78.1% for the evening window. That is 13 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 3,108 flights scheduled in it.

Across the week, Tuesday is the strongest day at 88.7% on time and Friday the weakest at 76.5%. 12 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week84.4Mon88.7Tue87.0Wed82.1Thu76.5Fri83.8Sat79.1Sun
Monday: 84.4 percent on time. Tuesday: 88.7 percent on time. Wednesday: 87.0 percent on time. Thursday: 82.1 percent on time. Friday: 76.5 percent on time. Saturday: 83.8 percent on time. Sunday: 79.1 percent on time

Carrier by carrier

Which airlines ran best at SEA in October

The choice of carrier is not cosmetic here. SkyWest Airlines arrives on time 89.5% of the time; Southwest Airlines manages 74.4%. Sample sizes sit next to every figure, because a two-point gap across 626 flights means less than a ten-point one.

Carriers at SEA in October 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Alaska Airlines6,18179.8%51 min2.22%B
Delta Air Lines2,78083.9%66 min0.36%B+
SkyWest Airlines2,53289.5%57 min0.20%A+
United Airlines79687.2%67 min0.25%A+
Southwest Airlines62674.4%44 min0.16%C+
American Airlines57386.2%55 min0.17%A+
Hawaiian Airlinesthin sample15577.1%133 min1.29%B
Frontier Airlinesthin sample12180.5%172 min2.48%B
JetBlue Airwaysthin sample5086.0%183 min0.00%A+
Envoy Airthin sample4582.2%84 min0.00%B+

The spread between SkyWest and Southwest is 15 points, wide enough that it should decide the booking. On a hundred trips that is 15 more arrivals inside the on-time window.

Route by route

Busiest routes out of SEA in October

Routes from SEA in October 2025
RouteFlightsOn timeAvg delayCancelledGrade
SEA to LAX · Los Angeles61486.1%70 min1.30%A
SEA to PHX · Phoenix59979.5%57 min0.50%B+
SEA to SFO · San Francisco58473.0%61 min1.20%C
SEA to DEN · Denver55783.2%48 min0.72%B+
SEA to ANC · Anchorage55376.7%51 min1.63%B
SEA to ORD · Chicago49681.1%53 min0.60%B+
SEA to LAS · Las Vegas48776.2%82 min2.46%B
SEA to GEG · Spokane45189.0%57 min0.89%A+
SEA to DFW · Dallas-Fort Worth44282.2%58 min0.68%B+
SEA to PDX · Portland42888.0%35 min0.70%A+
SEA to SJC · San Jose39284.5%47 min1.02%B
SEA to SMF · Sacramento37584.9%45 min0.80%B+
SEA to SLC · Salt Lake City36585.6%62 min1.37%A
SEA to SAN · San Diegothin sample34875.4%48 min2.30%B
SEA to SNA · Santa Anathin sample34182.0%57 min1.76%B
SEA to BOI · Boisethin sample33391.6%55 min0.00%A+
SEA to ATL · Atlantathin sample29585.2%85 min1.02%A
SEA to JFK · New Yorkthin sample27375.9%66 min1.83%B
SEA to HNL · Honoluluthin sample24877.6%90 min1.21%B
SEA to MSP · Minneapolisthin sample23091.2%45 min1.30%A
SEA to BOS · Bostonthin sample22772.4%66 min0.88%C+
SEA to PSC · Pascothin sample21384.4%50 min0.94%B+
SEA to EWR · Newarkthin sample20681.3%58 min1.46%B
SEA to ONT · Ontariothin sample20087.9%69 min1.00%A
SEA to OAK · Oaklandthin sample17879.7%42 min0.56%B+

Delay causes

What held SEA up in October

One category carries most of the weight here. Carrier accounts for 50% of the 135,000 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.

  • Carrier
    50%
  • Late-arriving aircraft
    26%
  • National Airspace System
    21%
  • Extreme weather
    4%
  • Security
    0%

The largest share of delay minutes, 50%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 68,000 of the 135,000 delay minutes reported here. The split is drawn from 135,182 reported delay minutes.

Cancellations sit at 1.16% against a national 0.53%, which is ordinary. Diversions add another 0.17%.

Badly late arrivals are rare here: only 4.5% land an hour or more behind schedule, against 6.3% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

What to do with this

Flying from SEA in October

For a October trip through SEA: expect 82.9% on time and 1.16% cancelled, going by October 2025. 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.