Best Time to Fly ORD to MSO: On-Time Stats by Hour & Airline
Chicago O'Hare International → Missoula Montana
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 79.5% of Chicago (ORD) to Missoula (MSO) flights arrived on time (499 scheduled flights). That is 1.9 points above the national average of 77.6%.
United Airlines was the most punctual of the 3 airlines on the route at 89.3%, while Envoy Air trailed at 76.2%.
May has been the best month (98% on time) and Friday the weakest day of the week (73%).
0.4% of flights were cancelled, versus 1.8% nationally.
ORD to MSO on-time performance by airline
Last 12 months. Airlines with fewer than 30 completed flights are marked “limited data”.
| Airline | On time | Avg delay when late | Cancelled | Flights |
|---|---|---|---|---|
| United Airlines | 89.3% | 60 min | 1.0% | 104 |
| SkyWest Airlines | 82.3% | 53 min | 1.9% | 53 |
| Envoy Air | 76.2% | 55 min | 0.0% | 342 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ORD to MSO
On-time arrival % by scheduled departure hour (local time), 806 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 8am–9am | 88.7% | 1.1% | 188 |
| 9am–10am | 80.4% | 0.0% | 492 |
| 10am–11am | Limited data | 6 | |
| 3pm–4pm | Limited data | 5 | |
| 4pm–5pm | Limited data | 1 | |
| 5pm–6pm | Limited data | 1 | |
| 7pm–8pm | Limited data | 5 | |
| 8pm–9pm | 66.4% | 0.9% | 108 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ORD to MSO
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 15 | ||
| Summer peak (Jun 15 - Aug 15) | 81.3% | +0.4 pts | 0.3% | 312 |
| All other days | 80.9% | — | 0.4% | 479 |
Monthly on-time trend
On-time arrival % each month, with the 12-month US average for reference.
What causes delays on this route
Share of reported delay minutes, last 12 months (BTS cause categories).