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.
SDF → MDW
Louisville to Chicago: 1,001 nonstop flights a year
On time (12 months)
85%
Cancelled
1.6%
avg delay 10 min
Best time to leave
Before 9 AM
92% on time vs 78% 6 to 9 PM
Most reliable airline
Southwest
84% chance on time
Lowest nonstop fare seen in the next two months: $303 (Southwest 2130 on 2026-10-21). 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 2816
8:55 AM → 9:15 AM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-30.
89%
chance on time
- On time (history)
- 96%
- Cancelled
- 0.0%
- Avg arrival delay
- 4 min
- Arrived on time 96% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 92% on time; 6 to 9 PM: 78%).
- Lands inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 2816 fares Opens this date on Aviasales#2 · Southwest 1407
8:40 AM → 9:00 AM1h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 3146; its record covers all of them.
88%
chance on time
- On time (history)
- 89%
- Cancelled
- 0.0%
- Avg arrival delay
- 12 min
- Arrived on time 89% of the time (70 flights, Jun 2025 to May 2026).
- Never cancelled in 71 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 92% on time; 6 to 9 PM: 78%).
- Lands inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
Moderate track record · 70 flights
Find Southwest 1407 fares Opens this date on Aviasales#3 · Southwest 2035
11:50 AM → 12:05 PM1h 15m nonstop
Local times, typical schedule. Last flown 2026-04-06.
81%
chance on time
- On time (history)
- 73%
- Cancelled
- 0.0%
- Avg arrival delay
- 20 min
- Arrived on time 73% of the time (33 flights, Jun 2025 to May 2026).
- Never cancelled in 33 scheduled flights.
- Lands inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
- Short track record (33 flights), so its score leans on the airline's record at this hour.
Limited track record · 33 flights
Find Southwest 2035 fares Opens this date on Aviasales#4 · Southwest 1683
2:40 PM → 2:55 PM1h 15m nonstop
Local times, typical schedule. Last flown 2026-05-29.
79%
chance on time
- On time (history)
- 74%
- Cancelled
- 0.0%
- Avg arrival delay
- 15 min
- Arrived on time 74% of the time (38 flights, Jun 2025 to May 2026).
- Never cancelled in 39 scheduled flights.
- 81% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (38 flights), so its score leans on the airline's record at this hour.
Limited track record · 38 flights
Find Southwest 1683 fares Opens this date on Aviasales#5 · Southwest 300
8:10 PM → 8:25 PM1h 15m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 3305; its record covers all of them.
76%
chance on time
- On time (history)
- 73%
- Cancelled
- 1.6%
- Avg arrival delay
- 18 min
- Arrived on time 73% of the time (59 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 78% on time; Before 9 AM: 92%).
- 51% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (59 flights), so its score leans on the airline's record at this hour.
Limited track record · 59 flights
Find Southwest 300 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines84%
1,001 flights · 85% 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%
359 flights · avg delay 6 min
- 9 AM to noon84%
58 flights · avg delay 9 min
- Noon to 3 PM88%
166 flights · avg delay 7 min
- 3 to 6 PM80%
91 flights · avg delay 17 min
- 6 to 9 PM78%
304 flights · avg delay 16 min
Best day: Saturday (92%). Worst: Sunday (83%).
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