Routes › Charleston (CHS) › CHS to SEA
Route · 12 months to July 2026
Charleston to Seattle: on-time record
Charleston AFB/International to Seattle/Tacoma International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
In the 12 months to July 2026, reporting carriers scheduled 347 flights from Charleston (CHS) to Seattle (SEA), a distance of 2,415 miles. 73.5% of them arrived within 15 minutes of schedule.
That is 2.5 points below the national on-time share of 76.0% for the same period and 4.0 points below the 77.5% recorded for all departures from CHS. Flights that did arrive were 6.2 min late on average, and 0.6% of scheduled flights were cancelled (national: 1.8%).
Alaska Airlines is the only reporting carrier on the route, with 347 flights in the period.
The on-time share is up 1.3 points on the previous 12 months (72.2%); cancellations moved from 1.4% to 0.6%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, late-arriving aircraft 40%, national aviation system 39% and air carrier 19%.
- On time 73.5%
- Arrived 15+ minutes late 25.9%
- Cancelled 0.6%
- Diverted 0.0%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| AS Alaska Airlines | 347 | 100% | 73.5% | 6.2 min | 0.6% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | CHS to SEA | All departures from CHS | All arrivals at SEA | All reported flights |
|---|---|---|---|---|
| Arrived on time | 73.5% | 77.5% | 78.8% | 76.0% |
| Arrived 15+ minutes late | 25.9% | 19.8% | 20.0% | 21.9% |
| Cancelled | 0.6% | 2.3% | 1.1% | 1.8% |
| Diverted | 0.0% | 0.4% | 0.1% | 0.3% |
| Average arrival delay | 6.2 min | 8.6 min | 3.1 min | 8.1 min |
| Delay minutes per 100 flights | 1,211 | 1,770 | 1,281 | 1,684 |
| Scheduled flights | 347 | 24,565 | 164,830 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, SEA to CHS, recorded 86.7% on time across 347 flights in the same period.
Month by month
Year on year: on time 73.5% against 72.2% (+1.3 pts), cancelled 0.6% against 1.4%, flights 347 against 349.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 72 | 76.4% | 9.7% | -6.2 min | 3 |
| Feb | 74 | 89.2% | 0.0% | -5.2 min | 3 |
| Mar | 93 | 86.0% | 0.0% | -6.4 min | 3 |
| Apr | 90 | 66.7% | 0.0% | 6.2 min | 3 |
| May | 93 | 69.9% | 1.1% | 2.2 min | 3 |
| Jun | 90 | 72.2% | 0.0% | 8.7 min | 3 |
| Jul | 93 | 61.3% | 1.1% | 15.2 min | 3 |
| Aug | 93 | 66.7% | 3.2% | 11.3 min | 3 |
| Sep | 90 | 78.9% | 0.0% | 2.0 min | 3 |
| Oct | 91 | 85.7% | 1.1% | -10.3 min | 3 |
| Nov | 79 | 72.2% | 0.0% | 5.9 min | 3 |
| Dec | 89 | 77.5% | 1.1% | -2.8 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from Charleston (CHS)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| CHS–ATL | Charleston to Atlanta | 3,221 | 87.8% | -3.4 min | 1.8% |
| CHS–CLT | Charleston to Charlotte | 2,498 | 81.7% | 6.5 min | 1.8% |
| CHS–ORD | Charleston to Chicago | 2,106 | 75.0% | 8.6 min | 2.5% |
| CHS–DCA | Charleston to Washington | 1,751 | 69.0% | 23.2 min | 4.5% |
| CHS–LGA | Charleston to New York | 1,471 | 71.1% | 16.3 min | 5.7% |
| CHS–EWR | Charleston to Newark | 1,341 | 76.1% | 11.0 min | 3.6% |
| CHS–BWI | Charleston to Baltimore | 1,233 | 80.5% | 2.3 min | 1.5% |
| CHS–DFW | Charleston to Dallas/Fort Worth | 1,227 | 78.1% | 8.0 min | 2.3% |
All 29 routes and the airport record for CHS · airport record for SEA
Questions and answers
How often are flights from Charleston to Seattle on time?
73.5% of the 347 flights scheduled from CHS to SEA in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from CHS to SEA?
Alaska Airlines is the only reporting carrier with at least 60 flights on the route in the period, so there is no comparison to make.
What causes delays between Charleston and Seattle?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 40%, national aviation system 39%, air carrier 19%, security 2%, extreme weather 1%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from CHS?
Too few departure hours carry enough flights on this route to compare them.
Is it getting better?
The on-time share for the 12 months to July 2026 was 73.5%, up 1.3 points on the previous 12 months (72.2%). The monthly chart on this page shows each of the last 36 months. Across those months, February had the highest on-time share (89.2%) and July the lowest (61.3%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.