ATIS Alerts Smart Flight Search
Find the flight least likely to be delayed
BetaWe rank real flight numbers by how often they flew and arrived on time over the last 12 months, adjusted for your travel month and departure time, then check nearby airports and calmer connections. US airlines and airports.
LAX → MDW
Los Angeles to Chicago: 1,355 nonstop flights a year
On time (12 months)
80%
Cancelled
0.5%
avg delay 11 min
Best time to leave
Before 9 AM
91% on time vs 63% 3 to 6 PM
Most reliable airline
Southwest
80% chance on time
Lowest nonstop fare seen in the next two months: $148 (Southwest 1772 on 2026-11-05). 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 2341
5:05 AM → 11:05 AM4h 00m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 493; its record covers all of them.
88%
chance on time
- On time (history)
- 88%
- Cancelled
- 3.4%
- Avg arrival delay
- 5 min
- Arrived on time 88% of the time (84 flights, Jun 2025 to May 2026).
- Cancelled 3.4% of the time (3 of 87).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 3 to 6 PM: 63%).
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
Moderate track record · 84 flights
Find Southwest 2341 fares Opens this date on Aviasales#2 · Southwest 991
11:55 PM → 5:50 AM3h 55m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1537; its record covers all of them.
84%
chance on time
- On time (history)
- 81%
- Cancelled
- 0.0%
- Avg arrival delay
- 7 min
- Arrived on time 81% of the time (85 flights, Jun 2025 to May 2026).
- Never cancelled in 87 scheduled flights.
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
Moderate track record · 85 flights
Find Southwest 991 fares Opens this date on Aviasales#3 · Southwest 1508
11:05 AM → 5:00 PM3h 55m nonstop
Local times, typical schedule. Last flown 2026-05-30.
78%
chance on time
- On time (history)
- 79%
- Cancelled
- 0.0%
- Avg arrival delay
- 20 min
- Arrived on time 79% of the time (24 flights, Jun 2025 to May 2026).
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
- Short track record (24 flights), so its score leans on the airline's record at this hour.
Limited track record · 24 flights
Find Southwest 1508 fares Opens this date on Aviasales#4 · Southwest 2867
4:45 PM → 10:40 PM3h 55m nonstop
Local times, typical schedule. Last flown 2026-05-29.
70%
chance on time
- On time (history)
- 59%
- Cancelled
- 0.0%
- Avg arrival delay
- 26 min
- Arrived on time 59% of the time (22 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 63% on time; Before 9 AM: 91%).
- Departs inside LAX's trouble window: 53% of its 15 ground stops and delay programs started between 4 PM and 10 PM.
- 61% of its delay minutes came from the plane arriving late from an earlier flight.
Limited track record · 22 flights
Find Southwest 2867 fares Opens this date on Aviasales#5 · Southwest 3223
11:35 AM → 5:30 PM3h 55m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 3067; its record covers all of them.
70%
chance on time
- On time (history)
- 56%
- Cancelled
- 2.5%
- Avg arrival delay
- 19 min
- Arrived on time 56% of the time (39 flights, Jun 2025 to May 2026).
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
- Short track record (39 flights), so its score leans on the airline's record at this hour.
Limited track record · 39 flights
Find Southwest 3223 fares Opens this date on Aviasales#6 · Southwest 3708
3:50 PM → 9:40 PM3h 50m nonstop
Local times, typical schedule. Last flown 2026-04-06.
64%
chance on time
- On time (history)
- 40%
- Cancelled
- 0.0%
- Avg arrival delay
- 29 min
- Arrived on time 40% of the time (15 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 63% on time; Before 9 AM: 91%).
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
- Short track record (15 flights), so its score leans on the airline's record at this hour.
Limited track record · 15 flights
Find Southwest 3708 fares Opens this date on Aviasales#7 · Southwest 1510
12:00 PM → 5:50 PM3h 50m nonstop
Local times, typical schedule. Last flown 2026-05-29.
56%
chance on time
- On time (history)
- 26%
- Cancelled
- 0.0%
- Avg arrival delay
- 26 min
- Arrived on time 26% of the time (23 flights, Jun 2025 to May 2026).
- Departs outside LAX's trouble window (4 PM to 10 PM, when 53% of its 15 ground stops and delay programs started).
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 1510 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines80%
1,355 flights · 80% on time as flown · 0.5% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM91%
435 flights · avg delay 6 min
- 9 AM to noon73%
183 flights · avg delay 14 min
- Noon to 3 PM66%
160 flights · avg delay 12 min
- 3 to 6 PM63%
198 flights · avg delay 23 min
- After 9 PM87%
365 flights · avg delay 6 min
Best day: Saturday (87%). Worst: Sunday (77%).
Smarter routing
Nearby airports that run more on time
ONT → MDW 90% chance on time
Ontario International Airport to Chicago Midway International Airport · 360 flights a year · 47 mi from your airports · yours: 80%
BUR → MDW 87% chance on time
Hollywood Burbank/Bob Hope Airport to Chicago Midway International Airport · 322 flights a year · 18 mi from your airports · yours: 80%
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