Best Time to Fly LAS to IAD: On-Time Stats by Hour & Airline
Harry Reid International → Washington Dulles International
Data through July 2026 · Last updated October 18, 2026
1,078 flights were scheduled from Las Vegas (LAS) to Washington (IAD) in the last 12 months, and 86.3% of those that flew arrived on time, 8.7 points above the US average of 77.6%.
Among 2 airlines, United Airlines led with 88.5% on time and Frontier Airlines was last with 64.3%.
Over 24 months, Tuesday was the most reliable day (90% on time) and July the worst month (72%).
The cancellation rate was 0.6% (US average 1.8%).
LAS 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 | 88.5% | 56 min | 0.6% | 980 |
| Frontier Airlines | 64.3% | 60 min | 0.0% | 98 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly LAS to IAD
On-time arrival % by scheduled departure hour (local time), 2,265 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 12am–1am | 61.1% | 0.0% | 72 |
| 7am–8am | 95.4% | 0.0% | 87 |
| 8am–9am | 88.7% | 0.3% | 672 |
| 12pm–1pm | Limited data | 24 | |
| 1pm–2pm | 82.8% | 0.6% | 662 |
| 2pm–3pm | Limited data | 24 | |
| 4pm–5pm | Limited data | 23 | |
| 10pm–11pm | 78.3% | 1.2% | 84 |
| 11pm–12am | 87.7% | 0.8% | 617 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on LAS 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) | 95.0% | +7.5 pts | 0.0% | 40 |
| Christmas & New Year (Dec 20 - Jan 3) | 89.0% | +1.5 pts | 0.0% | 73 |
| Summer peak (Jun 15 - Aug 15) | 76.0% | -11.6 pts | 0.0% | 417 |
| All other days | 87.5% | — | 0.7% | 1,735 |
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).