Route on-time record
STL to LAX: most on-time flights and the best time to fly
St Louis (St. Louis Lambert International Airport) to Los Angeles (Los Angeles International Airport). 1,029 nonstop flights in Jun 2025 to May 2026, 74% arrived within 15 minutes and 0.2% were cancelled. The most reliable flight number was Southwest 3243 at 8:30 AM.
Flying on a specific date? We’ll adjust for the month, the weekday and the forecast.
STL → LAX
St Louis to Los Angeles: 1,029 nonstop flights a year
On time (12 months)
74%
Cancelled
0.2%
avg delay 18 min
Best time to leave
9 AM to noon
84% on time vs 46% after 9 PM
Most reliable airline
Southwest
74% chance on time
Lowest nonstop fare seen in the next two months: $273 (Southwest 4712 on 2026-11-20). 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 3243
8:30 AM → 10:35 AM4h 05m nonstop
Local times, typical schedule. Last flown 2026-05-29.
81%
chance on time
- On time (history)
- 79%
- Cancelled
- 0.0%
- Avg arrival delay
- 9 min
- Arrived on time 79% of the time (39 flights, Jun 2025 to May 2026).
- Never cancelled in 39 scheduled flights.
Limited track record · 39 flights
Find Southwest 3243 fares Opens this date on Aviasales#2 · SkyWest 6293 · sold as United Express, Delta Connection, American Eagle or Alaska
6:35 AM → 8:50 AM4h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31.
78%
chance on time
- On time (history)
- 81%
- Cancelled
- 0.0%
- Avg arrival delay
- 26 min
- Arrived on time 81% of the time (72 flights, Jun 2025 to May 2026).
- Never cancelled in 72 scheduled flights.
Moderate track record · 72 flights
Find 6:35 AM flight fares Opens this date on Aviasales#3 · SkyWest 6216 · sold as United Express, Delta Connection, American Eagle or Alaska
6:21 AM → 8:37 AM4h 16m nonstop
Local times, typical schedule. Last flown 2026-05-20.
72%
chance on time
- On time (history)
- 68%
- Cancelled
- 2.7%
- Avg arrival delay
- 19 min
- Arrived on time 68% of the time (72 flights, Jun 2025 to May 2026).
Moderate track record · 72 flights
Find 6:21 AM flight fares Opens this date on Aviasales#4 · Southwest 952
9:40 PM → 11:45 PM4h 05m nonstop
Local times, typical schedule. Last flown 2026-05-31.
55%
chance on time
- On time (history)
- 45%
- Cancelled
- 0.0%
- Avg arrival delay
- 27 min
- Arrived on time 45% of the time (38 flights, Jun 2025 to May 2026).
- Never cancelled in 38 scheduled flights.
- Leaves in this route's least on-time window (After 9 PM: 46% on time; 9 AM to noon: 84%).
- 58% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 38 flights
Find Southwest 952 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines74%
675 flights · 74% on time as flown · 0.0% cancel
- SkyWest Airlines (sold as United Express, Delta Connection, American Eagle or Alaska)73%
349 flights · 73% on time as flown · 0.5% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM80%
592 flights · avg delay 18 min
- 9 AM to noon84%
107 flights · avg delay 10 min
- Noon to 3 PM71%
49 flights · avg delay 15 min
- 6 to 9 PM66%
173 flights · avg delay 18 min
- After 9 PM46%
92 flights · avg delay 31 min
Best day: Tuesday (79%). Worst: Monday (71%).
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
- Airline (crew, maintenance, boarding)58%
- Late-arriving aircraft26%
- Air traffic control and airport volume10%
- Severe weather7%
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 LAX questions
- What time of day is best to fly STL to LAX?
- 9 AM to noon: 84% of flights arrived on time, against 46% for departures after 9 PM.
- Which airline is most on time from STL to LAX?
- Southwest, with a season-adjusted 74% chance of operating and arriving on time over 675 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 LAX?
- June (65% on time); the best was November (85%), 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
- LAX 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 LAS 79%
- STL to DAL 77%
- STL to DTW 83%
- STL to MSP 80%
Most on-time flights from STL on every route →
Live status: FAA delays and ground stops