Holiday travel
Memorial Day at SEA
Seattle-Tacoma International Airport, Seattle, WA. July 2023 – July 2026. Set against SEA’s own ordinary days of the same weekday in the weeks around each holiday.
The window, year by year
The window runs the Saturday through the Monday, around Memorial Day (the last Monday of May). In the data: May 25–27, 2024; May 24–26, 2025; May 23–25, 2026. Three windows are in the data: enough to see whether a day repeats, not enough to call it a rule.
Memorial Day flights ran better than ordinary days in all three years. The gap ran from 2.7 points above usual in 2025 to 11.1 points above usual in 2024.
0.28% of scheduled departures were cancelled across the Memorial Day windows, against 0.47% on ordinary days of the same weekdays. It was lower in one of the three years.
| Year | Departures | On time | Usual | Gap, points | Cancelled | Usual |
|---|---|---|---|---|---|---|
| 2024May 25–27, 2024 | 1,361 | 87.2% | 76.1% | +11.1better | 0.00% | 0.47% |
| 2025May 24–26, 2025 | 1,447 | 78.8% | 76.1% | +2.7better | 0.28% | 0.47% |
| 2026May 23–25, 2026 | 1,439 | 83.7% | 76.1% | +7.6better | 0.56% | 0.47% |
| All years3 windows | 4,247 | 83.2% | 76.1% | +7.1better | 0.28% | 0.47% |
Day by day
Memorial Day was the worst day of the window in two of the three years. Over the years it ran 81.7% on time, still 5.7 points above an ordinary Monday.
The Sunday before Memorial Day was the best day of the window in two of the three years. Over the years it ran 84.0% on time, 10.0 points above an ordinary Sunday.
- Better than usual
- Worse than usual
- About the same
- What ordinary days of the same weekday had
- Lowest to highest single year
- Lighter bars: days just outside the window
Bars show the on-time arrival rate and start at 60%, not zero. A dashed stub is a day with too few flights to print a rate.
| Day | Departures against an ordinary day | On time | Usual | Gap, points | Cancelled | Each year: 2024, 2025, 2026 |
|---|---|---|---|---|---|---|
| Thursday beforeoutside the window | about the same | 76.5% | 75.3% | +1.2about the same | 0.47% | 72.9 · 77.7 · 78.8 |
| Friday beforeoutside the window | about the same | 78.3% | 76.2% | +2.1about the same | 0.33% | 73.7 · 80.2 · 81.1 |
| Saturday before | 2% fewer | 83.9% | 78.4% | +5.5better | 0.15% | 87.7 · 80.3 · 83.8 |
| Sunday before | 6% fewer | 84.0% | 74.0% | +10.0better | 0.43% | 88.5 · 77.0 · 86.8 |
| Memorial Day | about the same | 81.7% | 76.0% | +5.7better | 0.27% | 85.7 · 79.0 · 80.7 |
| Tuesday afteroutside the window | 3% more | 77.7% | 79.5% | −1.8about the same | 0.90% | 78.1 · 76.7 · 78.3 |
A dash means fewer than 120 flights stood behind the figure, or behind the ordinary days it would be compared with: too few to print a rate, and nothing is estimated in its place. “Usual” is what ordinary days of the same weekday had at the same place in the weeks around the holiday, weighted by the flights being compared.
Which departure times held up
The busiest days at SEA were Sunday, May 26, 2024 (445 departures), Monday, May 27, 2024 (492 departures), Sunday, May 25, 2025 (481 departures), Monday, May 26, 2025 (510 departures), Sunday, May 24, 2026 (481 departures), and Monday, May 25, 2026 (499 departures).
Across the whole window, flights leaving 5–9 AM had the highest on-time rate: 89.6%, 2.1 points above usual for that time of day. Those leaving 9 AM–12 PM had the lowest: 79.8%, still 3.9 points above usual for that time of day.
The holiday helped flights leaving 3–6 PM the most (11.2 points above usual for that time of day) and those leaving 5–9 AM the least (2.1 points above).
On each year’s two busiest days, flights leaving 5–9 AM had the highest on-time rate: 89.8%, 2.5 points above usual for that time of day. Those leaving 9 PM–5 AM had the lowest: 80.0%, still 11.3 points above usual for that time of day.
The holiday helped flights leaving 3–6 PM the most (11.9 points above usual for that time of day) and those leaving 5–9 AM the least (2.5 points above).
| Leaving | On time, whole window | Usual | Gap, points | On time, busiest days | Usual | Gap, points |
|---|---|---|---|---|---|---|
| 5–9 AM | 89.6% | 87.5% | +2.1about the same | 89.8% | 87.3% | +2.5about the same |
| 9 AM–12 PM | 79.8% | 75.9% | +3.9better | 80.9% | 74.9% | +6.0better |
| 12–3 PM | 81.1% | 72.8% | +8.3better | 81.2% | 73.3% | +7.9better |
| 3–6 PM | 82.7% | 71.5% | +11.2better | 82.2% | 70.3% | +11.9better |
| 6–9 PM | 82.6% | 73.4% | +9.2better | 81.1% | 71.9% | +9.2better |
| 9 PM–5 AM | 82.3% | 71.4% | +10.9better | 80.0% | 68.7% | +11.3better |
SEA beside every covered airport
Storms and outages move whole regions at once. This puts SEA’s year beside the year of all covered airports together, each against its own usual, to show whether SEA did better or worse than the network.
| Year | SEA on time | SEA, gap from usual | All airports on time | All airports, gap from usual |
|---|---|---|---|---|
| 2024May 25–27, 2024 | 87.2% | +11.1 | 72.7% | −2.3 |
| 2025May 24–26, 2025 | 78.8% | +2.7 | 76.4% | +1.4 |
| 2026May 23–25, 2026 | 83.7% | +7.6 | 75.0% | 0.0 |
For every holiday at once, see the five holidays at SEA, or the network view.