CHS to SEA flight delays
Charleston, SC (CHS) Seattle, WA (SEA) · 2,415 miles
347 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
71.22%
Arrived on time
Within 15 minutes of schedule
0.86%
Cancelled
Share of scheduled flights
39 min
When late, late by
Average across delayed arrivals
13 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In February it ran 37.3 points more punctual than in July — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
The two directions do not behave alike. SEA to CHS arrives on time 13.7 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
The route has been getting better. The later months in the record run 11.6 points more punctual than the earlier ones, which usually means a schedule that was too tight has been given more room.
This route does worse than its own airport. CHS as a whole runs 8.8 points more punctual than these flights, which points at something specific to the route — the time of day it is scheduled, or the aircraft that feed it — rather than the airport.
Which airline should you fly on this route?
Over January 2025 – August 2026, Alaska Airlines arrived on time most often on CHS to SEA. Flights ran closest to schedule in February and worst in July.
Every airline on CHS to SEA
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Alaska Airlines | 347 | 71.22% | 0.86% | 39 min | D |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
SEA to CHS Seattle back to Charleston 84.93% on time BOther routes from Charleston
Common questions
Are flights from Charleston to Seattle usually delayed?
71.22% of flights on the CHS to SEA route arrived within 15 minutes of schedule, so roughly 3 in every ten arrived late. That is worse than the average route in this record.
Which airlines fly from Charleston to Seattle?
Only Alaska Airlines appears in the published record on this route, with 347 flights and 71.22% arriving on time.
How often are CHS to SEA flights cancelled?
0.86% of scheduled flights did not operate — about 9 in every thousand. That is in the normal range.
What is the best month to fly Charleston to Seattle?
February, when 84% of flights arrived on time. The worst was July at 46.7%.
When CHS to SEA flights are late, how late are they?
About 39 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on CHS to SEA during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →