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 → BUF
Chicago to Buffalo: 830 nonstop flights a year
On time (12 months)
75%
Cancelled
1.3%
avg delay 13 min
Best time to leave
Before 9 AM
89% on time vs 54% after 9 PM
Most reliable airline
Southwest
74% chance on time
Lowest nonstop fare seen in the next two months: $261 (Southwest 4008 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 1093
7:45 AM → 10:15 AM1h 30m nonstop
Local times, typical schedule. Last flown 2026-05-31. Same departure also flew as Southwest 537; its record covers all of them.
88%
chance on time
- On time (history)
- 96%
- Cancelled
- 0.0%
- Avg arrival delay
- 3 min
- Arrived on time 96% of the time (46 flights, Jun 2025 to May 2026).
- Never cancelled in 46 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 89% on time; After 9 PM: 54%).
- Departs inside MDW's trouble window: 50% of its 30 ground stops and delay programs started between 7 AM and 1 PM.
Limited track record · 46 flights
Find Southwest 1093 fares Opens this date on Aviasales#2 · Southwest 3490
8:00 AM → 10:30 AM1h 30m nonstop
Local times, typical schedule. Last flown 2026-04-06.
80%
chance on time
- On time (history)
- 89%
- Cancelled
- 3.6%
- Avg arrival delay
- 12 min
- Arrived on time 89% of the time (27 flights, Jun 2025 to May 2026).
- Leaves in this route's most on-time window (Before 9 AM: 89% on time; After 9 PM: 54%).
- 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 (27 flights), so its score leans on the airline's record at this hour.
Limited track record · 27 flights
Find Southwest 3490 fares Opens this date on Aviasales#3 · Southwest 694
12:55 PM → 3:25 PM1h 30m nonstop
Local times, typical schedule. Last flown 2026-05-29. Same departure also flew as Southwest 2436, 4332; its record covers all of them.
75%
chance on time
- On time (history)
- 76%
- Cancelled
- 1.5%
- Avg arrival delay
- 15 min
- Arrived on time 76% of the time (66 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.
- 55% of its delay minutes came from the plane arriving late from an earlier flight.
Moderate track record · 66 flights
Find Southwest 694 fares Opens this date on Aviasales#4 · Southwest 2164
7:05 PM → 9:30 PM1h 28m nonstop
Local times, typical schedule. Last flown 2026-05-31.
72%
chance on time
- On time (history)
- 76%
- Cancelled
- 0.0%
- Avg arrival delay
- 15 min
- Arrived on time 76% 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 2164 fares Opens this date on Aviasales#5 · Southwest 2238
3:35 PM → 6:00 PM1h 28m nonstop
Local times, typical schedule. Last flown 2026-05-31.
70%
chance on time
- On time (history)
- 69%
- Cancelled
- 0.0%
- Avg arrival delay
- 13 min
- Arrived on time 69% of the time (16 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).
- Short track record (16 flights), so its score leans on the airline's record at this hour.
Limited track record · 16 flights
Find Southwest 2238 fares Opens this date on Aviasales#6 · Southwest 2834
6:50 PM → 9:15 PM1h 25m nonstop
Local times, typical schedule. Last flown 2026-04-06.
69%
chance on time
- On time (history)
- 63%
- Cancelled
- 3.0%
- Avg arrival delay
- 19 min
- Arrived on time 63% 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).
- Short track record (32 flights), so its score leans on the airline's record at this hour.
Limited track record · 32 flights
Find Southwest 2834 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines74%
830 flights · 75% on time as flown · 1.3% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM89%
100 flights · avg delay 7 min
- 9 AM to noon84%
166 flights · avg delay 9 min
- Noon to 3 PM76%
206 flights · avg delay 11 min
- 3 to 6 PM68%
81 flights · avg delay 16 min
- 6 to 9 PM71%
194 flights · avg delay 18 min
- After 9 PM54%
83 flights · avg delay 18 min
Best day: Wednesday (80%). Worst: Sunday (70%).
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