Best Time to Fly ONT to BWI: On-Time Stats by Hour & Airline
Ontario International → Baltimore/Washington International Thurgood Marshall
Data through July 2026 · Last updated October 18, 2026
Over the last 12 months, 83.9% of Ontario (ONT) to Baltimore (BWI) flights arrived on time (281 scheduled flights). That is 6.3 points above the national average of 77.6%.
Southwest Airlines was the only reporting airline with regular flights on this route.
Over 24 months, Saturday was the most reliable day (90% on time) and July the worst month (79%).
The cancellation rate was 0.4% (US average 1.8%).
ONT to BWI 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 |
|---|---|---|---|---|
| Southwest Airlines | 83.9% | 44 min | 0.4% | 281 |
80%+ good 70–79.9% fair <70% poor
Best time of day to fly ONT to BWI
On-time arrival % by scheduled departure hour (local time), 338 flights over 24 months.
Show the numbers
| Departure hour | On time | Cancelled | Flights |
|---|---|---|---|
| 5am–6am | Limited data | 1 | |
| 7am–8am | Limited data | 1 | |
| 9am–10am | Limited data | 29 | |
| 10am–11am | 93.9% | 2.9% | 34 |
| 11am–12pm | Limited data | 13 | |
| 12pm–1pm | 78.0% | 0.0% | 50 |
| 9pm–10pm | 82.4% | 0.0% | 210 |
Best day of the week
24 months, by day of departure.
Best month to fly
24 months, by calendar month.
Holiday travel on ONT to BWI
On-time arrivals during holiday periods compared with all other days, last 24 months.
| Period | On time | vs other days | Cancelled | Flights |
|---|---|---|---|---|
| Thanksgiving week (Tue before to Mon after) | Limited data | 6 | ||
| Christmas & New Year (Dec 20 - Jan 3) | Limited data | 11 | ||
| Summer peak (Jun 15 - Aug 15) | 80.7% | -2.7 pts | 0.0% | 109 |
| All other days | 83.4% | — | 0.5% | 212 |
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).