Best Time to Fly STT to IAD: On-Time Stats by Hour & Airline
Cyril E King → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 81.9% of Charlotte Amalie (STT) to Washington (IAD) flights arrived on time (336 scheduled flights). That is 4.3 points above the national average of 77.6%.
United Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Monday was the most reliable day (86% on time) and August the worst month (70%).
The cancellation rate was 1.8% (US average 1.8%).
STT to IAD 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 |
|---|---|---|---|---|
| United Airlines | 81.9% | 67 min | 1.8% | 336 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly STT to IAD
On-time arrival % by scheduled departure hour (local time), 645 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12pm–1pm | 79.2% | 0.0% | 74 |
| 1pm–2pm | 87.0% | 1.6% | 251 |
| 4pm–5pm | 82.2% | 1.0% | 300 |
| 5pm–6pm | Limited data | 20 | |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on STT to IAD
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) | Limited data | 14 | ||
| Christmas & New Year (Dec 20 - Jan 3) | 86.0% | +0.9 pts | 4.4% | 45 |
| Summer peak (Jun 15 - Aug 15) | 77.3% | -7.8 pts | 0.0% | 132 |
| All other days | 85.2% | — | 1.3% | 454 |
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).