BWI to ONT flight delays & on-time performance
Nonstop flights from Baltimore/Washington International Thurgood Marshall Airport to Ontario International Airport · 2,283 miles · Aug 2025 – Jul 2026
No FAA-reported ground stops or delays at BWI or ONT right now. Individual flights can still be delayed by the airline; check with your airline for your flight.
Key facts
- Flights from Baltimore (BWI) to Ontario (ONT) arrived on time 63% of the time in Aug 2025 – Jul 2026, worse than the 78% national average.
- 0.4% were cancelled, and 8% arrived an hour or more late.
- Southwest Airlines is the only airline reporting nonstop flights on this route.
- Departures scheduled around 9am did best (84% on time); around 1pm did worst (56%).
- Wednesday was the most reliable day to fly (74% on time) and Saturday the least (52%).
- The largest source of delay minutes was airline (crew, maintenance, cleaning, fueling) (46%).
Which airline is most on time from BWI to ONT?
Ranked by on-time arrival rate. Regional airlines fly under their partner's brand (e.g. SkyWest for Delta Connection or United Express).
| Airline | On time | Cancelled | Avg delay | 1 hr+ late | Flights |
|---|---|---|---|---|---|
| Southwest Airlines | 63% | 0.4% | 19 min | 7.5% | 281 |
Best time of day to fly
On-time arrival rate by scheduled departure hour (local time).
- 9am84%58 flights
- 11am73%15 flights
- 12pm63%32 flights
- 1pm56%39 flights
- 2pm71%17 flights
- 3pm58%40 flights
- 5pm18%11 flights
- 8pm58%45 flights
Best day of the week
On-time arrival rate by day of departure.
- Monday68%0.0% cancelled
- Tuesday64%2.7% cancelled
- Wednesday74%0.0% cancelled
- Thursday63%0.0% cancelled
- Friday61%0.0% cancelled
- Saturday52%0.0% cancelled
- Sunday63%0.0% cancelled
On-time trend by month
Why flights are late
Share of delay minutes by cause, as reported by airlines to the DOT.
- Airline (crew, maintenance, cleaning, fueling)46%
- Late-arriving aircraft37%
- Air traffic control & airport congestion15%
- Extreme weather1%
- Security0%
Why flights are cancelled
Share of cancellations by reason.
- Airline (crew, maintenance, cleaning, fueling)100%
- Extreme weather0%
- Air traffic control & airport congestion0%
- Security0%
BWI to ONT: common questions
- How often are BWI to ONT flights on time?
- 63% of flights arrived less than 15 minutes late in Aug 2025 – Jul 2026, compared with 78% for all US flights.
- How often are flights from Baltimore to Ontario cancelled?
- 0.4% of scheduled flights were cancelled (1 of 281).
- How long are typical delays?
- Across all flights the average arrival delay was 19 min (early arrivals count as zero). Flights that were late arrived 48 min behind schedule on average, and 7.5% of flights were an hour or more late.
- How long is taxi time at BWI?
- Flights on this route spent 14 min taxiing from the gate to takeoff on average.
Related routes
Return trip: ONT to BWI — 84% on time
More flights from Baltimore
Data: U.S. DOT Bureau of Transportation Statistics, Aug 2025 – Jul 2026 (12 months). Latest month published by BTS: July 2026. Route: BWI → ONT, nonstop flights by US airlines that report to the DOT. How we calculate this.