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5 nonstop, 35 with 1 connection, 6 with 2 · ranked by overall best · 24 hidden by your Most reliable time setting (they leave at other times of day) · showing the top 3
Most reliable time: morning departures (5–11 AM), the window with the best on-time odds for this trip. Turn off “Most reliable” under Departure time in Advanced settings to see every time.
Fares seen on this date: nonstop from 118 (recent searches, one way, per person; each card opens the live price)
22 matching trips
Why this is our top pick
- This morning flight leaves in the most reliable time of day on this route: its best departures have an 85% reliability rating vs 64% for midday departures.
- United trips we compared arrive on time 84% of the time on average, 3 points more often than Frontier and Delta (81%).
- It has the same 30 in of legroom as the next-best option (United 1140 on the Boeing 737-800); it arrives on time 2 points more often; it flies a newer plane (about 12 vs 18 years old).
5:30 AM5:32 PMLAS → IAD
United · UA 596 / UA 2853
9h 02m1 stop
3h 30m in DEN
One ticket
89%arrive on time99% connections madeCheck fares
Aircraft and legroom reflect the planes each flight has flown recently. Airlines can swap planes and seat maps change, so check the airline’s seat map when you book.
LAS → IAD
Las Vegas to Dulles: 1,130 nonstop flights a year
On time (12 months)
87%
Cancelled
0.5%
avg delay 7 min
Best time to leave
Before 9 AM
92% on time vs 83% noon to 3 PM
Most reliable airline
United
88% chance on time
Lowest nonstop fare seen in the next two months: $118 (Frontier 4278 on 2026-11-20). Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- United Airlines88%
1,037 flights · 88% on time as flown · 0.6% cancel
- Frontier Airlines81%
93 flights · 72% on time as flown · 0.3% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM92%
361 flights · avg delay 4 min
- Noon to 3 PM83%
361 flights · avg delay 10 min
- After 9 PM86%
407 flights · avg delay 8 min
Best day: Tuesday (91%). Worst: Sunday (81%).
Historical odds, not a guarantee. Built from the US DOT Bureau of Transportation Statistics on-time reports (Jun 2025 to May 2026), FAA ground stop and delay program advisories, and 20 years of airport weather observations. Covers US airlines that report to the DOT; schedules are flights operated recently, so confirm times when you book. ATIS Alerts is not affiliated with any airline. Fares are what Aviasales travelers saw in recent searches (USD, one way, 1 adult), not live quotes; the partner site shows the current price. Fare links go to our travel partner and may earn us a commission at no cost to you. Affiliate disclosure