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.
DEN → MDW
Denver to Chicago: 2,385 nonstop flights a year
On time (12 months)
73%
Cancelled
1.7%
avg delay 17 min
Best time to leave
Before 9 AM
93% on time vs 53% 6 to 9 PM
Most reliable airline
Southwest
72% chance on time
Lowest nonstop fare seen in the next two months: $226 (Southwest 2775 on 2026-10-30). 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 1939
6:35 AM → 9:55 AM2h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31.
90%
chance on time
- On time (history)
- 95%
- Cancelled
- 0.0%
- Avg arrival delay
- 5 min
- Arrived on time 95% of the time (55 flights, Jun 2025 to May 2026).
- Never cancelled in 55 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 6 to 9 PM: 53%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 55 flights
Find Southwest 1939 fares Opens this date on Aviasales#2 · Southwest 2613
6:20 AM → 9:45 AM2h 25m nonstop
Local times, typical schedule. Last flown 2026-04-06.
88%
chance on time
- On time (history)
- 94%
- Cancelled
- 6.1%
- Avg arrival delay
- 6 min
- Arrived on time 94% of the time (31 flights, Jun 2025 to May 2026).
- Cancelled 6.1% of the time (2 of 33).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 6 to 9 PM: 53%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 31 flights
Find Southwest 2613 fares Opens this date on Aviasales#3 · Southwest 482
8:25 AM → 11:50 AM2h 25m nonstop
Local times, typical schedule. Last flown 2026-05-31.
85%
chance on time
- On time (history)
- 87%
- Cancelled
- 0.0%
- Avg arrival delay
- 7 min
- Arrived on time 87% of the time (47 flights, Jun 2025 to May 2026).
- Never cancelled in 47 scheduled flights.
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 6 to 9 PM: 53%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 47 flights
Find Southwest 482 fares Opens this date on Aviasales#4 · Southwest 2115
8:10 AM → 11:35 AM2h 25m nonstop
Local times, typical schedule. Last flown 2026-04-06.
84%
chance on time
- On time (history)
- 90%
- Cancelled
- 12.1%
- Avg arrival delay
- 4 min
- Arrived on time 90% of the time (29 flights, Jun 2025 to May 2026).
- Cancelled 12.1% of the time (4 of 33).
- Leaves in this route's most on-time window (Before 9 AM: 93% on time; 6 to 9 PM: 53%).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
Limited track record · 29 flights
Find Southwest 2115 fares Opens this date on Aviasales#5 · Southwest 2761
10:25 AM → 1:50 PM2h 25m nonstop
Local times, typical schedule. Last flown 2026-04-06.
81%
chance on time
- On time (history)
- 87%
- Cancelled
- 6.1%
- Avg arrival delay
- 8 min
- Arrived on time 87% of the time (31 flights, Jun 2025 to May 2026).
- Cancelled 6.1% of the time (2 of 33).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Short track record (31 flights), so its score leans on the airline's record at this hour.
Limited track record · 31 flights
Find Southwest 2761 fares Opens this date on Aviasales#6 · Southwest 1941
11:00 AM → 2:20 PM2h 20m nonstop
Local times, typical schedule. Last flown 2026-05-31.
81%
chance on time
- On time (history)
- 87%
- Cancelled
- 1.8%
- Avg arrival delay
- 5 min
- Arrived on time 87% of the time (54 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 ground stops and delay programs started).
- Short track record (54 flights), so its score leans on the airline's record at this hour.
Limited track record · 54 flights
Find Southwest 1941 fares Opens this date on Aviasales#7 · Southwest 1475
1:40 PM → 5:05 PM2h 25m nonstop
Local times, typical schedule. Last flown 2026-05-27.
78%
chance on time
- On time (history)
- 88%
- Cancelled
- 0.0%
- Avg arrival delay
- 4 min
- Arrived on time 88% of the time (16 flights, Jun 2025 to May 2026).
- Departs outside DEN's trouble window (2 PM to 8 PM, when 79% of its 174 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 1475 fares Opens this date on Aviasales#8 · Southwest 1942
2:45 PM → 6:05 PM2h 20m nonstop
Local times, typical schedule. Last flown 2026-05-29. Same departure also flew as Southwest 1447; its record covers all of them.
62%
chance on time
- On time (history)
- 58%
- Cancelled
- 3.6%
- Avg arrival delay
- 25 min
- Arrived on time 58% of the time (53 flights, Jun 2025 to May 2026).
- Cancelled 3.6% of the time (2 of 56).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
- Short track record (53 flights), so its score leans on the airline's record at this hour.
Limited track record · 53 flights
Find Southwest 1942 fares Opens this date on Aviasales#9 · Southwest 1840
6:05 PM → 9:30 PM2h 20m nonstop
Local times, typical schedule. Last flown 2026-04-06.
60%
chance on time
- On time (history)
- 44%
- Cancelled
- 3.6%
- Avg arrival delay
- 36 min
- Arrived on time 44% of the time (27 flights, Jun 2025 to May 2026).
- Leaves in this route's least on-time window (6 to 9 PM: 53% on time; Before 9 AM: 93%).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 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 1840 fares Opens this date on Aviasales#10 · Southwest 1590
5:35 PM → 9:05 PM2h 30m nonstop
Local times, typical schedule. Last flown 2026-05-31.
60%
chance on time
- On time (history)
- 68%
- Cancelled
- 1.9%
- Avg arrival delay
- 20 min
- Arrived on time 68% of the time (53 flights, Jun 2025 to May 2026).
- Departs inside DEN's trouble window: 79% of its 174 ground stops and delay programs started between 2 PM and 8 PM.
- 57% of its delay minutes came from the plane arriving late from an earlier flight.
- Short track record (53 flights), so its score leans on the airline's record at this hour.
Limited track record · 53 flights
Find Southwest 1590 fares Opens this date on Aviasales
Airlines on this route
Season-adjusted chance of operating and arriving on time.
- Southwest Airlines72%
2,271 flights · 73% on time as flown · 1.8% cancel
- Frontier Airlines68%
114 flights · 66% on time as flown · 1.4% cancel
On time by departure time
All airlines, scheduled local departure, Jun 2025 to May 2026.
- Before 9 AM93%
633 flights · avg delay 4 min
- 9 AM to noon83%
382 flights · avg delay 8 min
- Noon to 3 PM74%
510 flights · avg delay 14 min
- 3 to 6 PM57%
411 flights · avg delay 30 min
- 6 to 9 PM53%
393 flights · avg delay 32 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