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ATIS Alerts Smart Flight Search

Find the flight least likely to be delayed

Beta

We 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 → SDF

Chicago to Louisville: 1,002 nonstop flights a year

On time (12 months)

80%

Cancelled

1.6%

avg delay 13 min

Best time to leave

Before 9 AM

92% on time vs 59% after 9 PM

Most reliable airline

Southwest

79% chance on time

Check MDW to SDF fares

Lowest nonstop fare seen in the next two months: $307 (Southwest 139 on 2026-10-24). 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. #1 · Southwest 833

    7:45 AM → 9:55 AM1h 10m nonstop

    Local times, typical schedule. Last flown 2026-05-30. Same departure also flew as Southwest 3360; its record covers all of them.

    89%

    chance on time

    On time (history)
    95%
    Cancelled
    3.2%
    Avg arrival delay
    6 min
    • Arrived on time 95% of the time (60 flights, Jun 2025 to May 2026).
    • Cancelled 3.2% of the time (2 of 62).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 59%).
    • 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 · 60 flights

    Find Southwest 833 fares Opens this date on Aviasales

  2. #2 · Southwest 733

    8:05 AM → 10:25 AM1h 18m nonstop

    Local times, typical schedule. Last flown 2026-04-05. Same departure also flew as Southwest 533; its record covers all of them.

    87%

    chance on time

    On time (history)
    100%
    Cancelled
    0.0%
    Avg arrival delay
    0 min
    • Arrived on time 100% of the time (18 flights, Jun 2025 to May 2026).
    • Leaves in this route's most on-time window (Before 9 AM: 92% on time; After 9 PM: 59%).
    • Departs inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
    • Short track record (18 flights), so its score leans on the airline's record at this hour.

    Limited track record · 18 flights

    Find Southwest 733 fares Opens this date on Aviasales

  3. #3 · Southwest 1324

    12:50 PM → 3:05 PM1h 15m nonstop

    Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 3374, 2837, 4536; its record covers all of them.

    77%

    chance on time

    On time (history)
    79%
    Cancelled
    1.2%
    Avg arrival delay
    10 min
    • Arrived on time 79% of the time (81 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 · 81 flights

    Find Southwest 1324 fares Opens this date on Aviasales

  4. #4 · Southwest 3376

    6:45 PM → 9:00 PM1h 15m nonstop

    Local times, typical schedule. Last flown 2026-05-31.

    77%

    chance on time

    On time (history)
    80%
    Cancelled
    0.0%
    Avg arrival delay
    12 min
    • Arrived on time 80% of the time (46 flights, Jun 2025 to May 2026).
    • Never cancelled in 46 scheduled flights.
    • 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 (46 flights), so its score leans on the airline's record at this hour.

    Limited track record · 46 flights

    Find Southwest 3376 fares Opens this date on Aviasales

  5. #5 · Southwest 1678

    7:40 PM → 9:55 PM1h 15m nonstop

    Local times, typical schedule. Last flown 2026-04-06.

    73%

    chance on time

    On time (history)
    69%
    Cancelled
    3.0%
    Avg arrival delay
    14 min
    • Arrived on time 69% of the time (32 flights, Jun 2025 to May 2026).
    • Cancelled 3.0% of the time (1 of 33).
    • Departs outside MDW's trouble window (7 AM to 1 PM, when 50% of its 30 ground stops and delay programs started).
    • 69% of its delay minutes came from the plane arriving late from an earlier flight.

    Limited track record · 32 flights

    Find Southwest 1678 fares Opens this date on Aviasales

Airlines on this route

Season-adjusted chance of operating and arriving on time.

  • Southwest Airlines79%

    1,002 flights · 80% on time as flown · 1.6% cancel

On time by departure time

All airlines, scheduled local departure, Jun 2025 to May 2026.

  • Before 9 AM92%

    114 flights · avg delay 7 min

  • 9 AM to noon91%

    231 flights · avg delay 5 min

  • Noon to 3 PM80%

    173 flights · avg delay 11 min

  • 3 to 6 PM72%

    139 flights · avg delay 19 min

  • 6 to 9 PM76%

    272 flights · avg delay 16 min

  • After 9 PM59%

    73 flights · avg delay 24 min

Best day: Wednesday (84%). Worst: Sunday (78%).

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