Which departure time was most reliable for DAL to COS?
Among qualifying DAL-to-COS departure window results, Early morning had the highest on-time rate: 93.0% of 100 flights. Night was lowest at 55.8% across 120 flights.
| Departure window | Flights | On time | 30+ min | Cancelled |
|---|---|---|---|---|
| Early morning | 100 | 93.0% | 3.0% | 2.0% |
| Late morning | 196 | 91.3% | 5.6% | 0.0% |
| Afternoon | 190 | 73.7% | 13.2% | 1.1% |
| Evening | 215 | 56.7% | 29.3% | 0.9% |
| Night | 120 | 55.8% | 29.2% | 0.8% |
Which weekday was most reliable for DAL to COS?
Among qualifying DAL-to-COS weekday results, Saturday had the highest on-time rate: 80.7% of 83 flights. Sunday was lowest at 66.7% across 120 flights.
| Day | Flights | On time | 30+ min | Cancelled |
|---|---|---|---|---|
| Monday | 132 | 72.0% | 17.4% | 0.8% |
| Tuesday | 115 | 79.1% | 13.0% | 0.9% |
| Wednesday | 110 | 75.5% | 14.5% | 0.0% |
| Thursday | 129 | 69.8% | 19.4% | 0.8% |
| Friday | 132 | 72.0% | 18.2% | 0.8% |
| Saturday | 83 | 80.7% | 15.7% | 1.2% |
| Sunday | 120 | 66.7% | 17.5% | 1.7% |
Which airline was most reliable for DAL to COS?
Only Southwest Airlines met the DAL-to-COS airline threshold: 73.2% of 821 scheduled flights arrived on time during July 2025–June 2026.
| Airline | Flights | On time | 30+ min | Cancelled |
|---|---|---|---|---|
| Southwest Airlines | 821 | 73.2% | 16.7% | 0.9% |
Which month was most reliable for DAL to COS?
Among qualifying DAL-to-COS month results, September 2025 had the highest on-time rate: 82.2% of 73 flights. June 2026 was lowest at 60.0% across 60 flights.
| Month | Flights | On time | 30+ min | Cancelled |
|---|---|---|---|---|
| July 2025 | 84 | 63.1% | 22.6% | 0.0% |
| August 2025 | 75 | 68.0% | 18.7% | 0.0% |
| September 2025 | 73 | 82.2% | 15.1% | 0.0% |
| October 2025 | 74 | 77.0% | 10.8% | 1.4% |
| November 2025 | 74 | 73.0% | 14.9% | 2.7% |
| December 2025 | 75 | 77.3% | 12.0% | 0.0% |
| January 2026 | 66 | 81.8% | 7.6% | 4.5% |
| February 2026 | 67 | 80.6% | 13.4% | 0.0% |
| March 2026 | 60 | 71.7% | 20.0% | 0.0% |
| April 2026 | 56 | 78.6% | 10.7% | 1.8% |
| May 2026 | 57 | 64.9% | 21.1% | 0.0% |
| June 2026 | 60 | 60.0% | 35.0% | 0.0% |
What drove DAL to COS delay minutes?
Late aircraft was the largest recorded DAL-to-COS delay category, accounting for 64.1% of 12,128 BTS-attributed delay minutes during July 2025–June 2026.
Weather, schedules and operations change. For a trip you have already booked, use the airline or airport for live status.