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.
BUF → MDW
Buffalo to Chicago: 829 nonstop flights a year
On time (12 months)
78%
Cancelled
1.2%
avg delay 13 min
Best time to leave
Before 9 AM
91% on time vs 59% 6 to 9 PM
Most reliable airline
Southwest
78% chance on time
Lowest nonstop fare seen in the next two months: $244 (Southwest 3867 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 2345
6:00 AM → 6:40 AM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-29.
88%
chance on time
- On time (history)
- 90%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 90% of the time (39 flights, Jun 2025 to May 2026).
- Never cancelled in 39 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 59%).
- Short track record (39 flights), so its score leans on the airline's record at this hour.
Limited track record · 39 flights
Find Southwest 2345 fares Opens this date on Aviasales#2 · Southwest 3686
8:25 AM → 9:05 AM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 1295; its record covers all of them.
84%
chance on time
- On time (history)
- 89%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 89% of the time (18 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 59%).
- 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 (18 flights), so its score leans on the airline's record at this hour.
Limited track record · 18 flights
Find Southwest 3686 fares Opens this date on Aviasales#3 · Southwest 1303
5:45 AM → 6:35 AM1h 50m nonstop
Local times, typical schedule. Last flown 2026-04-06.
84%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.0%
- Avg arrival delay
- 17 min
- Arrived on time 87% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 59%).
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 1303 fares Opens this date on Aviasales#4 · Southwest 935
11:25 AM → 12:05 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-29.
82%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.0%
- Avg arrival delay
- 13 min
- Arrived on time 87% of the time (23 flights, Jun 2025 to May 2026).
- 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 935 fares Opens this date on Aviasales#5 · Southwest 1862
8:00 AM → 8:40 AM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-30.
82%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 3 min
- Arrived on time 88% of the time (8 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 91% on time; 6 to 9 PM: 59%).
- 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 (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 1862 fares Opens this date on Aviasales#6 · Southwest 342
3:10 PM → 3:50 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-27.
79%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 14 min
- Arrived on time 88% of the time (16 flights, Jun 2025 to May 2026).
- Short track record (16 flights), so its score leans on the airline's record at this hour.
Limited track record · 16 flights
Find Southwest 342 fares Opens this date on Aviasales#7 · Southwest 754
12:15 PM → 12:55 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-04-01.
78%
chance on time
- On time (history)
- 75%
- Cancelled
- 0.0%
- Avg arrival delay
- 12 min
- Arrived on time 75% of the time (8 flights, Jun 2025 to May 2026).
- 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 (8 flights), so its score leans on the airline's record at this hour.
Limited track record · 8 flights
Find Southwest 754 fares Opens this date on Aviasales#8 · Southwest 2737
6:55 PM → 7:35 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-27.
74%
chance on time
- On time (history)
- 69%
- Cancelled
- 0.0%
- Avg arrival delay
- 23 min
- Arrived on time 69% of the time (16 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 59% on time; Before 9 AM: 91%).
- 75% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (16 flights), so its score leans on the airline's record at this hour.
Limited track record · 16 flights
Find Southwest 2737 fares Opens this date on Aviasales#9 · Southwest 1305
12:05 PM → 12:50 PM1h 45m nonstop
Local times, typical schedule. Last flown 2026-04-06.
71%
chance on time
- On time (history)
- 43%
- Cancelled
- 6.7%
- Avg arrival delay
- 17 min
- Arrived on time 43% of the time (14 flights, Jun 2025 to May 2026).
- 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 (14 flights), so its score leans on the airline's record at this hour.
Limited track record · 14 flights
Find Southwest 1305 fares Opens this date on Aviasales#10 · Southwest 4020
8:00 PM → 8:40 PM1h 40m nonstop
Local times, typical schedule. Last flown 2026-05-29.
61%
chance on time
- On time (history)
- 52%
- Cancelled
- 0.0%
- Avg arrival delay
- 26 min
- Arrived on time 52% of the time (23 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 59% on time; Before 9 AM: 91%).
- 60% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (23 flights), so its score leans on the airline's record at this hour.
Limited track record · 23 flights
Find Southwest 4020 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines78%
829 flights · 78% on time as flown · 1.2% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM91%
357 flights · avg delay 6 min
- 9 AM to noon82%
50 flights · avg delay 10 min
- Noon to 3 PM80%
89 flights · avg delay 8 min
- 3 to 6 PM74%
89 flights · avg delay 21 min
- 6 to 9 PM59%
239 flights · avg delay 24 min
Best day: Tuesday (88%). Worst: Sunday (76%).
Smarter routing
Nearby airports that run more on time
ROC → MDW 81% chance on time
Frederick Douglass Greater Rochester International Airport to Chicago Midway International Airport · 431 flights a year · 55 mi from your airports · yours: 77%
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