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.
MDW → SAN
Chicago to San Diego: 1,066 nonstop flights a year
On time (12 months)
74%
Cancelled
1.0%
avg delay 14 min
Best time to leave
Before 9 AM
86% on time vs 64% 3 to 6 PM
Most reliable airline
Southwest
74% chance on time
Lowest nonstop fare seen in the next two months: $143 (Southwest 1071 on 2026-11-03). 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 1357
6:40 AM → 8:55 AM4h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31.
83%
chance on time
- On time (history)
- 83%
- Cancelled
- 0.0%
- Avg arrival delay
- 7 min
- Arrived on time 83% of the time (53 flights, Jun 2025 to May 2026).
- Never cancelled in 54 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 86% on time; 3 to 6 PM: 64%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
Limited track record · 53 flights
Find Southwest 1357 fares Opens this date on Aviasales#2 · Southwest 3994
6:05 AM → 8:35 AM4h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
83%
chance on time
- On time (history)
- 86%
- Cancelled
- 0.0%
- Avg arrival delay
- 11 min
- Arrived on time 86% of the time (28 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 86% on time; 3 to 6 PM: 64%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
- Lands inside SAN's trouble window: 66% of its 164 ground stops and delay programs started between 6 AM and noon.
Limited track record · 28 flights
Find Southwest 3994 fares Opens this date on Aviasales#3 · Southwest 2305
10:05 AM → 12:20 PM4h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1186, 2126; its record covers all of them.
70%
chance on time
- On time (history)
- 69%
- Cancelled
- 2.3%
- Avg arrival delay
- 17 min
- Arrived on time 69% of the time (86 flights, Jun 2025 to May 2026).
- Departs inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
Moderate track record · 86 flights
Find Southwest 2305 fares Opens this date on Aviasales#4 · Southwest 3996
4:05 PM → 6:35 PM4h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
68%
chance on time
- On time (history)
- 67%
- Cancelled
- 3.6%
- Avg arrival delay
- 18 min
- Arrived on time 67% of the time (27 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (3 to 6 PM: 64% on time; Before 9 AM: 86%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
- Short track record (27 flights), so its score leans on the airline's record at this hour.
Limited track record · 27 flights
Find Southwest 3996 fares Opens this date on Aviasales#5 · Southwest 3591
8:45 PM → 11:10 PM4h 25m nonstop
Local times, typical schedule. Last flown 2026-05-29.
65%
chance on time
- On time (history)
- 59%
- Cancelled
- 4.3%
- Avg arrival delay
- 17 min
- Arrived on time 59% of the time (22 flights, Jun 2025 to May 2026).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
- 51% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (22 flights), so its score leans on the airline's record at this hour.
Limited track record · 22 flights
Find Southwest 3591 fares Opens this date on Aviasales#6 · Southwest 3541
5:25 PM → 7:45 PM4h 20m nonstop
Local times, typical schedule. Last flown 2026-05-30.
65%
chance on time
- On time (history)
- 57%
- Cancelled
- 0.0%
- Avg arrival delay
- 20 min
- Arrived on time 57% of the time (47 flights, Jun 2025 to May 2026).
- Never cancelled in 47 scheduled flights.
- Leaves in this route's least on-time window (3 to 6 PM: 64% on time; Before 9 AM: 86%).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
Limited track record · 47 flights
Find Southwest 3541 fares Opens this date on Aviasales#7 · Southwest 2815
8:55 PM → 11:25 PM4h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
64%
chance on time
- On time (history)
- 58%
- Cancelled
- 5.0%
- Avg arrival delay
- 28 min
- Arrived on time 58% of the time (19 flights, Jun 2025 to May 2026).
- Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
- 86% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (19 flights), so its score leans on the airline's record at this hour.
Limited track record · 19 flights
Find Southwest 2815 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines74%
1,066 flights · 74% on time as flown · 1.0% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM86%
346 flights · avg delay 7 min
- 9 AM to noon69%
151 flights · avg delay 16 min
- Noon to 3 PM75%
151 flights · avg delay 15 min
- 3 to 6 PM64%
134 flights · avg delay 18 min
- 6 to 9 PM67%
268 flights · avg delay 19 min
Best day: Wednesday (80%). Worst: Sunday (72%).
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