Numbers from Aug 2025 – Jul 2026 flight records · generated 1 October 2026
GateCast grades your connection from A to F on how likely you are to make it, using a year of real flight records. At Seattle, pairs of Delta flights scheduled 45–59 minutes apart were missed on 12% of the days they ran, Aug 2025 – Jul 2026; pairs 90–120 minutes apart, on 4%.
How often Delta connections here were missed
Every pair of Delta flights at Seattle (regional flights sold as Delta included), grouped by the scheduled time between them, and checked against what actually happened on each day both flights ran, Aug 2025 – Jul 2026.
"Missed" means the first flight was cancelled, or arrived too late to leave about 31 minutes to get off, reach the next gate and board before the doors close. That time is our estimate for Delta connections here: flight records don't say which passengers made their connection. Days when the second flight was cancelled aren't counted. Pairs scheduled less than 35 minutes apart are left out, because we can't tell which of those the airline would sell as a connection.
When Delta connections at Seattle go wrong
From the same flight records as the chart above, and with the same meaning of "missed".
How long a connection to look for
Delta connections of 60–89 minutes here were missed on 7% of days. No shorter connection time in the chart above was missed on fewer than 1 day in 10.
Time of day
Delta connections of 45–59 minutes at Seattle were missed on 8% of days when the first flight was due in before 10:00, and on 16% when it was due in at 18:00 or later.
| First flight due in | 35–44 min | 45–59 min | 60–89 min | 90–120 min |
|---|---|---|---|---|
| before 10:00 | 12% | 8% | 4% | 3% |
| 10:00–13:59 | 22% | 12% | 6% | 4% |
| 14:00–17:59 | 22% | 13% | 6% | 5% |
| 18:00 or later | 27% | 16% | 9% | 6% |
Share of days missed, by scheduled arrival time (Seattle local time) and scheduled time between the flights. "—": fewer than 500 days to go on.
Time of year
The month with the most missed Delta connections at Seattle was December 2025: 14% of days. The fewest was September 2025: 6%. The first flight was cancelled or diverted most often in March 2026, on 2.5% of days, against 0.2% in August 2025.
| Month | Days missed | First flight cancelled |
|---|---|---|
| Aug 2025 | 7% | 0.2% |
| Sep 2025 | 6% | 0.2% |
| Oct 2025 | 7% | 0.5% |
| Nov 2025 | 9% | 1.3% |
| Dec 2025 | 14% | 2.2% |
| Jan 2026 | 11% | 1.9% |
| Feb 2026 | 8% | 1.2% |
| Mar 2026 | 11% | 2.5% |
| Apr 2026 | 6% | 0.4% |
| May 2026 | 7% | 0.5% |
| Jun 2026 | 8% | 0.4% |
| Jul 2026 | 9% | 1.0% |
"First flight cancelled" includes flights diverted to another airport. "—": fewer than 500 days to go on.
The last flight of the day
Of Delta's scheduled flights leaving Seattle at 18:00 or later, 23 of 49 are its last flight of the day to that city: miss the connection and the next Delta flight there leaves the next day. Before 10:00 it is 2 of 58. Connections onto a last flight of the day were missed on 10% of days; connections with a later Delta flight to the same city, on 8%.
How late Delta flights into Seattle ran
Over 43,108 scheduled Delta flights into Seattle, Aug 2025 – Jul 2026, 16% arrived 15 or more minutes late and 5% an hour or more late. The typical flight arrived at the gate 10 minutes early. 1.1% were cancelled or diverted.
What decides a connection at Seattle
- At Seattle, half of travellers arriving from abroad without Global Entry waited 22 minutes or less at passport control, and 1 in 10 waited more than 57 minutes (24 September 2025 – 23 September 2026).US Customs and Border Protection, Airport Wait Times (awt.cbp.gov), 24 September 2025 – 23 September 2026, checked 25 September 2026
- Almost all international arrivals at Seattle collect their checked bags, clear US customs, check them in again and go back through security before the next flight. On some routes, eligible connecting passengers skip the bag recheck but still go back through security: for example, Korean Air and Delta from Seoul (since June 2026, according to the airlines' announcement). Check with your airline. Flights that clear US preclearance before they leave are also an exception. It runs at 16 airports (ten in Canada, including Toronto, Montreal and Vancouver, plus Dublin, Shannon, Nassau, Bermuda, Aruba and Abu Dhabi), though not on every flight from them; a flight that clears it arrives at Seattle as a domestic flight. Your airline can tell you whether yours does.Korean Air and Delta joint release, 23 June 2026, as carried by Future Travel Experience (futuretravelexperience.com); US Customs and Border Protection, help.cbp.gov article 1244; US Customs and Border Protection, Preclearance locations and hours (cbp.gov/travel/preclearance, last modified 24 June 2026); Aer Lingus, "US immigration and pre-clearance" (mediacentre.aerlingus.com: no preclearance on its late Dublin departures to New York and Boston), checked 1 October 2026
What real connections here look like
Real Delta connections at Seattle from last year's flights. Each is the typical case of its kind, not the worst we found. Schedules change, so these exact flights may not run on your date.
40 minutes between flights looks tight — but on 85% of the 110 days both flights ran, the first one got in with enough time for a typical connection here. Graded B.
Graded over the 110 days both flights ran, Aug 2025 – Jul 2026 · generated 1 October 2026 · local times
1h 31m looks like plenty of time. But the first flight arrived more than an hour late on 16% of the 191 days both flights ran, and the connection was missed on 15% of them. Graded D.
Graded over the 191 days both flights ran, Aug 2025 – Jul 2026 · generated 1 October 2026 · local times
2h 05m between flights looks like plenty of room. But this is the last Delta flight of the day from SEA to RDU: miss it, and there's no later one that day, however long the wait was. The first flight got in too late on 3 of the 121 days both flights ran. Graded C; with another Delta flight an hour later it would be A.
Graded over the 121 days both flights ran, Aug 2025 – Jul 2026 · generated 1 October 2026 · local times
These are two separate tickets, not one booking. If the first flight runs late and you miss the second, you're not owed a seat on it. Passengers typically paid $206* one way from SEA to ORD. Graded C. The connection itself is rarely missed: the grade comes from the arrival. On the days both flights ran, Delta 2299 reached ORD typically on time, 14% of days more than an hour late.
Graded over the 89 days both flights ran, Aug 2025 – Jul 2026 · generated 1 October 2026 · local times
Typical fare passengers paid, one way, per ticket, from the US DOT fare survey (Jul 2024–Jun 2025). Fare only; bags and seats extra. Today's price may be different.
Check your own flights
Connecting through Seattle on different flights? Enter both flight numbers and the date.
Questions
Is 45 minutes enough for Delta at Seattle?
Over Aug 2025 – Jul 2026, pairs of Delta flights at Seattle scheduled 45–59 minutes apart were missed on 12% of the days they ran (658 flight pairs). Your own two flights can be much better or worse than that, so check them rather than going on the minutes alone.
Is an hour enough for Delta at Seattle?
Over Aug 2025 – Jul 2026, pairs of Delta flights at Seattle scheduled 60–89 minutes apart were missed on 7% of the days they ran (1,130 flight pairs). Your own two flights can be much better or worse than that, so check them rather than going on the minutes alone.
Read the full Seattle connection guide →
- US Customs and Border Protection, Airport Wait Times (awt.cbp.gov), 24 September 2025 – 23 September 2026, checked 25 September 2026
- Korean Air and Delta joint release, 23 June 2026, as carried by Future Travel Experience (futuretravelexperience.com); US Customs and Border Protection, help.cbp.gov article 1244; US Customs and Border Protection, Preclearance locations and hours (cbp.gov/travel/preclearance, last modified 24 June 2026); Aer Lingus, "US immigration and pre-clearance" (mediacentre.aerlingus.com: no preclearance on its late Dublin departures to New York and Boston), checked 1 October 2026
- Flight times, delays and cancellations: US Department of Transportation, Bureau of Transportation Statistics, On-Time Performance, Aug 2025 – Jul 2026
- Fares: US DOT fare survey (DB1B), Jul 2024-Jun 2025
Grades are estimates, not guarantees. Always check your airline's minimum connection time.
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