Best Time to Fly BOI to SEA: On-Time Stats by Hour & Airline
Boise Air Terminal → Seattle/Tacoma International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 85.2% of Boise (BOI) to Seattle (SEA) flights arrived on time (3,761 scheduled flights). That is 7.6 points above the national average of 77.6%.
Among 2 airlines, SkyWest Airlines led with 86.1% on time and Alaska Airlines was last with 82.4%.
Over 24 months, Tuesday was the most reliable day (88% on time) and August the worst month (78%).
The cancellation rate was 0.4% (US average 1.8%).
BOI to SEA on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| SkyWest Airlines | 86.1% | 60 min | 0.3% | 2,838 |
| Alaska Airlines | 82.4% | 49 min | 0.7% | 923 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly BOI to SEA
On-time arrival % by scheduled departure hour (local time), 7,466 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | 93.6% | 0.2% | 629 |
| 6am–7am | 93.2% | 0.5% | 566 |
| 7am–8am | 92.6% | 0.1% | 706 |
| 8am–9am | 85.6% | 0.0% | 521 |
| 9am–10am | 78.4% | 1.0% | 585 |
| 10am–11am | 87.3% | 0.4% | 537 |
| 11am–12pm | 88.4% | 0.3% | 295 |
| 12pm–1pm | 78.7% | 0.0% | 122 |
| 1pm–2pm | 84.2% | 0.6% | 477 |
| 2pm–3pm | 84.6% | 0.5% | 576 |
| 3pm–4pm | 80.5% | 0.0% | 257 |
| 4pm–5pm | 77.1% | 0.2% | 481 |
| 5pm–6pm | 83.6% | 0.2% | 531 |
| 6pm–7pm | 74.2% | 0.0% | 419 |
| 7pm–8pm | 78.0% | 0.3% | 571 |
| 8pm–9pm | 53.0% | 0.6% | 167 |
| 9pm–10pm | Limited data | 26 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on BOI to SEA
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | 72.6% | -12.7 pts | 0.0% | 125 |
| Christmas & New Year (Dec 20 - Jan 3) | 88.4% | +3.2 pts | 0.0% | 202 |
| Summer peak (Jun 15 - Aug 15) | 78.9% | -6.3 pts | 0.1% | 1,343 |
| All other days | 85.2% | — | 0.4% | 5,796 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).