Route profile
IAD→LAS
Flight reliability, delays and best times to fly from Washington to Las Vegas, 2,065 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 78% of comparable major US routes (4,598 compared)
Calculated from 3,180 flights. How this is calculated · What counts as on time
IAD → LAS arrives on time 83.0% of the time; the return trip, LAS → IAD, arrives on time 84.6% of the time.
IAD → LAS spends 29.1 minutes on the ground on a 2,065-mile trip: 20.7 minutes from pushback to wheels-up at IAD and 8.4 minutes from touchdown to gate at LAS.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where IAD to LAS differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
IAD to LAS is at its best against routes of similar length for flights scheduled at 7 PM: 80.2% arrive on time, 12.1 points ahead of the 68.1% those routes manage at that hour. Against all other routes the gap is 12.4 points.
IAD to LAS struggles most at 5 PM: 67.0% of its flights scheduled then arrive on time, 7.1 points behind the 74.1% on routes of similar length at the same hour.
IAD to LAS holds up on Sundays better than routes of similar length do: 82.3% on time to their 76.2%, a 6.1 points lead. Against all other routes the gap is 7.5 points.
March is kinder to IAD to LAS than to routes of similar length: 87.3% on time against 78.7%, 8.6 points better. Against all other routes the gap is 9.4 points.
United Airlines does better on IAD to LAS than on its routes of similar length: 83.9% on time here, 81.7% there, 2.2 points apart. Against all other routes the gap is 4 points.
IAD to LAS against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 7 PM departures | 80.2% | routes of similar length | 68.1% | +12.1 pts | 440 here, 38,545 there |
| Hour: 5 PM departures | 67.0% | routes of similar length | 74.1% | −7.1 pts | 370 here, 61,282 there |
| Weekday: Sunday | 82.3% | routes of similar length | 76.2% | +6.1 pts | 458 here, 138,413 there |
| Month: March | 87.3% | routes of similar length | 78.7% | +8.6 pts | 268 here, 76,150 there |
| Airline: United Airlines | 83.9% | routes of similar length | 81.7% | +2.2 pts | 2,973 here, 155,973 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 2,065 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
IAD to LAS in context
This route against IAD and LAS as a whole, against similar routes from IAD, and against its own first year, July 2023 – July 2026.
Leaving IAD, IAD to LAS is on time 83.0% of the time, 2.1 points better than the airport’s other departures at IAD (80.9%, from 164,422 flights).
Arriving at LAS, IAD to LAS is on time 83.0% of the time, 4.9 points better than the airport’s other arrivals at LAS (78.1%, from 560,732 flights).
Of the 2,728 flights scheduled in hours with at least 120 flights, 8 AM is the busiest hour with 711 (26.1%), 91.5% of them on time, and 6 PM the quietest with 146 (5.4%), 81.4% of them on time.
Airport comparisons take this route’s flights out of the airport total. Length means within 15% of this route’s distance, with at least 3 other routes from the same origin. On-time gaps are stated at 2 points and 2 standard errors, cancellation gaps at 0.5 points and 2 standard errors, and every group needs 750 flights. These are differences in the flights counted, not causes.
When it goes wrong
July 2023 – July 2026
37 min late
against a median of 11 min early
Percentiles over 3,180 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at LAS after arriving from IAD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 29% | High risk |
| 45 min | 16% | High risk |
| 60 min | 12% | Some risk |
| 90 min | 6.7% | Some risk |
| 120 min | 4.1% | Low risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 0.57% of the time and diverts 0.13% of the time, which a late arrival never shows up in.
Chance of missing is the share of 3,158 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 37 minutes late (90th-percentile gate arrival delay), over 3,180 operations.
Any other layover length: connection checker.
Best time to fly
IAD → LAS flights departing 5–9 AM arrived on time 89.4% of the time, against 66.7% for 3–6 PM departures, a gap of 22.7 percentage points.
By departure window
By departure hour
- 12 AM to 7 AM: too few flights to score
- 8 AM: 91.5% on time from 711 flights
- 9 AM: 86.7% on time from 427 flights
- 10 AM to 11 AM: too few flights to score
- 12 PM: 87.4% on time from 628 flights
- 1 PM to 4 PM: too few flights to score
- 5 PM: 67.0% on time from 374 flights
- 6 PM: 81.4% on time from 146 flights
- 7 PM: 80.2% on time from 442 flights
- 8 PM to 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why IAD → LAS runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
airspace and airport capacity, including weather-driven flow control
crew, maintenance, boarding and fueling, all within the carrier’s control
weather severe enough to stop this flight specifically
Share of the delay minutes US DOT attributed to each cause for IAD → LAS. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on IAD → LAS, at 43.1%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 89.4% of the time and 3–6 PM departures 66.7%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 2,995 | 83.9% | 0.60% | -11 min | 6.5% |
Weekly and seasonal patterns
By day of week
Wednesday is historically the most reliable day and Friday the least, a gap of 7.0 percentage points.
By month
- Jan: 77.7%
- Feb: 82.5%
- Mar: 87.3%
- Apr: 85.5%
- May: 82.1%
- Jun: 72.3%
- Jul: 72.2%
- Aug: 77.4%
- Sep: 91.3%
- Oct: 91.9%
- Nov: 92.4%
- Dec: 88.0%
July is historically the weakest month and November the strongest, a spread of 20.2 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: too few flights to score (60)
- August 2023: too few flights to score (62)
- September 2023: too few flights to score (61)
- October 2023: too few flights to score (62)
- November 2023: too few flights to score (61)
- December 2023: too few flights to score (62)
- January 2024: too few flights to score (77)
- February 2024: too few flights to score (83)
- March 2024: too few flights to score (90)
- April 2024: too few flights to score (90)
- May 2024: too few flights to score (84)
- June 2024: too few flights to score (60)
- July 2024: too few flights to score (62)
- August 2024: too few flights to score (57)
- September 2024: too few flights to score (80)
- October 2024: too few flights to score (93)
- November 2024: too few flights to score (89)
- December 2024: too few flights to score (80)
- January 2025: too few flights to score (92)
- February 2025: too few flights to score (100)
- March 2025: too few flights to score (100)
- April 2025: 74.8% from 120 flights
- May 2025: 76.8% from 144 flights
- June 2025: too few flights to score (111)
- July 2025: 70.7% from 123 flights
- August 2025: too few flights to score (119)
- September 2025: too few flights to score (91)
- October 2025: too few flights to score (93)
- November 2025: too few flights to score (89)
- December 2025: too few flights to score (92)
- January 2026: too few flights to score (90)
- February 2026: too few flights to score (74)
- March 2026: too few flights to score (80)
- April 2026: too few flights to score (81)
- May 2026: too few flights to score (86)
- June 2026: too few flights to score (90)
- July 2026: too few flights to score (92)
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 85.9% against 78.1% in the 12 months before — improving by 7.8 percentage points.
Data and methodology
Calculated by FlyerIntel from 3,180 IAD → LAS flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed