Las Vegas (LAS) to Washington (IAD): On-Time Performance
Data through May 2026
When you fly LAS to IAD matters as much as anything else about the booking: the route swung from 95% on-time in October 2025 to just 68% in July 2024. Across the full period the route averages 86% on-time against a national 78%.
- On-time
- 86%
- arrived <15 min late
- Avg delay
- 10 min
- completed flights
- Cancelled
- 0.7%
- Flights/day
- 3.1
- last 12 months
- Duration
- 4h 32m
- scheduled
- Distance
- 2,065 mi
Best airline from LAS to IAD
2 airlines flew this route regularly between 2024-06 and 2026-05.
| Airline | On-time | Avg delay | Cancelled | Flights |
|---|---|---|---|---|
| United Airlinesmost reliable | 87% | 10 min | 0.7% | 2,081 |
| Frontier Airlines | 73% | 18 min | 0.0% | 124 |
Monthly on-time trend
Best time to fly from LAS to IAD
Aim for departures around 7 a.m. (95% on-time); avoid 10 p.m. departures (78%).
By day of week
| Day | On-time | Avg delay |
|---|---|---|
| Monday | 85% | 13 min |
| Tuesdaybest | 93% | 5 min |
| Wednesday | 91% | 6 min |
| Thursday | 83% | 12 min |
| Friday | 85% | 8 min |
| Saturday | 87% | 8 min |
| Sunday | 81% | 18 min |
What causes delays on this route
Share of total delay minutes by cause, as reported by carriers to the US DOT.
- Late-arriving aircraft38%
- Airline operations41%
- National airspace system21%
Frequently asked questions
- How often are flights from LAS to IAD delayed?
- 14% of LAS–IAD flights arrived 15 or more minutes late (the US DOT definition of a delay) between 2024-06 and 2026-05. The average arrival delay across completed flights was 10 minutes.
- Which airline is most reliable from LAS to IAD?
- United Airlines has the best on-time record on this route at 87%, based on 2,081 flights. 2 airlines flew LAS–IAD frequently enough to compare in this period.
- What is the best time of day to fly from LAS to IAD?
- Departures around 7 a.m. have the best record (95% on-time), while departures around 10 p.m. have the worst (78%). As on most US routes, delays accumulate through the day, so earlier flights are generally safer.
- How long is the flight from LAS to IAD?
- The scheduled LAS–IAD flight time averages 4h 32m over 2,065 miles. Actual arrival times vary — flights on this route land 15+ minutes late 14% of the time.
- How often are LAS to IAD flights cancelled?
- 0.7% of scheduled flights on this route were cancelled between 2024-06 and 2026-05, at or below the national rate of 1.6%.
- What is the worst month to fly from LAS to IAD?
- July 2024 was the roughest month in this dataset, with only 68% of arrivals on time. The best was October 2025 at 95%. If your dates are flexible, that 26-point gap is worth planning around.
Explore related pages
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Related guides
Based on 2,205 flights, 2024-06–2026-05. Source: US DOT Bureau of Transportation Statistics. Updated 2026-07-01.