BWI to ONT flight delays
Baltimore, MD (BWI) Ontario, CA (ONT) · 2,283 miles
281 flights · January 2025 – August 2026 · US Bureau of Transportation Statistics
62.28%
Arrived on time
Within 15 minutes of schedule
0%
Cancelled
Share of scheduled flights
57 min
When late, late by
Average across delayed arrivals
23 min
Delay per flight
Averaged over every flight flown
What the record says about this route
The season swings this route hard. In September it ran 43.3 points more punctual than in April — a difference bigger than the one between the best and worst airlines on most routes. If the date is flexible, it is worth more than the carrier.
The two directions do not behave alike. ONT to BWI arrives on time 22 points more often than the outbound. Delay accumulates through the flying day, so whichever direction is scheduled later tends to carry the worse record — which is an argument for booking the morning departure if the choice exists.
This is a late route. Flights from Baltimore to Ontario miss their scheduled arrival often enough that a tight connection at the far end is a connection at risk.
The route has been getting worse. The later months run 11.2 points less punctual than the earlier ones. A drift of that size is rarely weather; it is more often an airline adding frequencies faster than the airports can absorb them.
Which airline should you fly on this route?
Over January 2025 – August 2026, Southwest Airlines arrived on time most often on BWI to ONT. Flights ran closest to schedule in September and worst in December.
Every airline on BWI to ONT
Ranked by how many flights each one operated. A carrier with fewer than 100 flights in the period is listed but not graded.
| Airline | Flights | On time | Cancelled | Avg delay | Grade |
|---|---|---|---|---|---|
| Southwest Airlines | 281 | 62.28% | 0% | 57 min | F |
Month by month
Share of flights that arrived within 15 minutes of schedule, by month flown.
The return leg
ONT to BWI Ontario back to Baltimore 84.29% on time BCommon questions
Are flights from Baltimore to Ontario usually delayed?
62.28% of flights on the BWI to ONT route arrived within 15 minutes of schedule, so roughly 4 in every ten arrived late. That is worse than the average route in this record.
Which airlines fly from Baltimore to Ontario?
Only Southwest Airlines appears in the published record on this route, with 281 flights and 62.28% arriving on time.
How often are BWI to ONT flights cancelled?
0% of scheduled flights did not operate — about 1 in every thousand. That is in the normal range.
What is the best month to fly Baltimore to Ontario?
September, when 90% of flights arrived on time. The worst was April at 46.7%.
When BWI to ONT flights are late, how late are they?
About 57 minutes on average across the flights that arrived more than 15 minutes behind schedule.
What these figures do and do not tell you
Everything on this page is counted from the flights that actually operated on BWI to ONT during January 2025 – August 2026, as reported by the airlines to the US Bureau of Transportation Statistics. "On time" is the federal definition: arriving at the gate within 15 minutes of the scheduled time.
A route's record is a description of the past, not a forecast. Weather, air traffic control and the aircraft's earlier flights that day drive most delays, and none of them are predictable from a historical rate. What the record does tell you is whether this route runs late more often than others, and which carrier on it has the better history — which is the part you can actually act on when you book.
Cancellations are counted separately from delays because they are a different problem for a traveller: a late flight still gets you there. How the grade is calculated →