Route on-time record
STL to LAS: most on-time flights and the best time to fly
St Louis (St. Louis Lambert International Airport) to Las Vegas (Harry Reid International Airport). 2,053 nonstop flights in Jun 2025 to May 2026, 79% arrived within 15 minutes and 0.5% were cancelled. The most reliable flight number was Southwest 3844 at 5:25 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
STL → LAS
St Louis to Las Vegas: 2,053 nonstop flights a year
On time (12 months)
79%
Cancelled
0.5%
avg delay 15 min
Best time to leave
Before 9 AM
93% on time vs 60% after 9 PM
Most reliable airline
Frontier
79% chance on time
Fares open on our travel partner (Aviasales). Pick the flight number you chose here.
Most reliable nonstop flights
Ranked by the chance the flight operates and arrives within 15 minutes of schedule, from Jun 2025 to May 2026 records.
#1 · Southwest 3844
5:25 AM → 7:10 AM3h 45m nonstop
Local times, typical schedule. Last flown 2026-04-06.
94%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 0 min
- Arrived on time 100% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; After 9 PM: 60%).
- Short track record (33 flights), so its score leans on the airline's record at this hour.
Limited track record · 33 flights
Find Southwest 3844 fares Opens this date on Aviasales#2 · Southwest 3153
6:00 AM → 7:30 AM3h 30m nonstop
Local times, typical schedule. Last flown 2026-05-30.
90%
chance on time
- On time (history)
- 92%
- Cancelled
- 0.0%
- Avg arrival delay
- 3 min
- Arrived on time 92% of the time (48 flights, Jun 2025 to May 2026).
- Never cancelled in 48 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; After 9 PM: 60%).
- Short track record (48 flights), so its score leans on the airline's record at this hour.
Limited track record · 48 flights
Find Southwest 3153 fares Opens this date on Aviasales#3 · Southwest 4602
7:05 AM → 8:45 AM3h 40m nonstop
Local times, typical schedule. Last flown 2026-04-06.
89%
chance on time
- On time (history)
- 100%
- Cancelled
- 0.0%
- Avg arrival delay
- 0 min
- Arrived on time 100% of the time (13 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; After 9 PM: 60%).
- Short track record (13 flights), so its score leans on the airline's record at this hour.
Limited track record · 13 flights
Find Southwest 4602 fares Opens this date on Aviasales#4 · Southwest 2464
8:20 AM → 9:50 AM3h 30m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 4656; its record covers all of them.
84%
chance on time
- On time (history)
- 83%
- Cancelled
- 0.0%
- Avg arrival delay
- 8 min
- Arrived on time 83% of the time (54 flights, Jun 2025 to May 2026).
- Never cancelled in 54 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; After 9 PM: 60%).
- Short track record (54 flights), so its score leans on the airline's record at this hour.
Limited track record · 54 flights
Find Southwest 2464 fares Opens this date on Aviasales#5 · Southwest 265
12:15 PM → 2:00 PM3h 45m nonstop
Local times, typical schedule. Last flown 2026-04-01.
82%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 18 min
- Arrived on time 88% of the time (8 flights, Jun 2025 to May 2026).
- Lands inside LAS's trouble window: 51% of its 104 ground stops and delay programs started between 10 AM and 4 PM.
- 96% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 265 fares Opens this date on Aviasales#6 · Southwest 757
9:35 AM → 11:20 AM3h 45m nonstop
Local times, typical schedule. Last flown 2026-04-06.
82%
chance on time
- On time (history)
- 85%
- Cancelled
- 0.0%
- Avg arrival delay
- 11 min
- Arrived on time 85% of the time (20 flights, Jun 2025 to May 2026).
- Lands inside LAS's trouble window: 51% of its 104 ground stops and delay programs started between 10 AM and 4 PM.
- 75% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (20 flights), so its score leans on the airline's record at this hour.
Limited track record · 20 flights
Find Southwest 757 fares Opens this date on Aviasales#7 · Frontier 3107
12:14 PM → 2:11 PM3h 50m nonstop
Local times, typical schedule. Last flown 2026-05-30.
81%
chance on time
- On time (history)
- 82%
- Cancelled
- 2.7%
- Avg arrival delay
- 24 min
- Arrived on time 82% of the time (108 flights, Jun 2025 to May 2026).
- Lands inside LAS's trouble window: 51% of its 104 ground stops and delay programs started between 10 AM and 4 PM.
Moderate track record · 108 flights
Find Frontier 3107 fares Opens this date on Aviasales#8 · Southwest 2620
5:35 PM → 7:15 PM3h 40m nonstop
Local times, typical schedule. Last flown 2026-04-06.
79%
chance on time
- On time (history)
- 78%
- Cancelled
- 0.0%
- Avg arrival delay
- 12 min
- Arrived on time 78% of the time (23 flights, Jun 2025 to May 2026).
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 2620 fares Opens this date on Aviasales#9 · Southwest 4545
2:15 PM → 4:00 PM3h 45m nonstop
Local times, typical schedule. Last flown 2026-04-06.
78%
chance on time
- On time (history)
- 82%
- Cancelled
- 0.0%
- Avg arrival delay
- 13 min
- Arrived on time 82% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- 61% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (33 flights), so its score leans on the airline's record at this hour.
Limited track record · 33 flights
Find Southwest 4545 fares Opens this date on Aviasales#10 · Frontier 2017
9:55 PM → 11:37 PM3h 42m nonstop
Local times, typical schedule. Last flown 2026-05-31.
76%
chance on time
- On time (history)
- 79%
- Cancelled
- 1.2%
- Avg arrival delay
- 33 min
- Arrived on time 79% of the time (168 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (After 9 PM: 60% on time; Before 9 AM: 93%).
Moderate track record · 168 flights
Find Frontier 2017 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Frontier Airlines79%
283 flights · 80% on time as flown · 1.3% cancel
- Southwest Airlines78%
1,770 flights · 78% on time as flown · 0.3% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM93%
594 flights · avg delay 3 min
- 9 AM to noon85%
137 flights · avg delay 10 min
- Noon to 3 PM77%
462 flights · avg delay 20 min
- 3 to 6 PM76%
234 flights · avg delay 13 min
- 6 to 9 PM69%
331 flights · avg delay 21 min
- After 9 PM60%
295 flights · avg delay 30 min
Best day: Tuesday (83%). Worst: Sunday (75%).
On time by month
All airlines, Jun 2023 to May 2026. Several years per month, so one stormy season doesn't define a month. Travel-month estimates use this seasonal pattern.
What delays this route
- Late-arriving aircraft47%
- Airline (crew, maintenance, boarding)35%
- Air traffic control and airport volume16%
- Severe weather1%
Share of delay minutes by the cause airlines report to the US DOT.
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
STL to LAS questions
- What time of day is best to fly STL to LAS?
- Before 9 AM: 93% of flights arrived on time, against 60% for departures after 9 PM. Later flights inherit delays from earlier ones, so the first departures of the day usually run best.
- Which airline is most on time from STL to LAS?
- Frontier, with a season-adjusted 79% chance of operating and arriving on time over 283 flights. The adjustment compares each airline with what the route did in the months it flew, so a carrier that skipped a stormy month gets no free credit.
- What is the worst month for delays on STL to LAS?
- July (70% on time); the best was November (87%), averaged over Jun 2023 to May 2026.
- Is this a prediction for my flight?
- No. These are historical odds from the US DOT on-time reports, FAA advisories and airport weather records. Check your flight status and the FAA delay board on the day you fly.
More routes from STL
- LAS to STL (return)
- STL to ATL 85%
- STL to DEN 75%
- STL to ORD 71%
- STL to LGA 75%
- STL to MCO 78%
- STL to DCA 73%
- STL to DFW 74%
- STL to PHX 76%
- STL to DAL 77%
- STL to DTW 83%
- STL to MSP 80%
- STL to CLT 83%
Live status: FAA delays and ground stops