Route reliability record
DFW→ONT
Dallas-Fort Worth to Ontario
- Flights
- 2,306
- Period
- July 2025 to June 2026
- Distance
- 1,188 mi
- Carriers
- 2
This route sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land about an hour behind schedule. That rests on 2,306 flights, with a median arrival 1 minutes early.
The national on-time rate over the same period is 77.6%, so this route runs 9 points behind the country as a whole. Across a thousand flights that is about 87 extra late arrivals.
Key figures
On time
68.9%
Arrivals under 15 minutes late, of 2,237 completed flights
Avg delay
66 min
Across delayed arrivals only, not all flights
Cancelled
2.91%
National rate is 1.81%
Best carrier
American
66.9% on time across 1,984 flights
These figures cover 2,306 flights between July 2025 and June 2026. Beyond the headline rate, 10.9% of arrivals land a full hour or more behind schedule. That is the number that wrecks a connection, and it is not visible in an on-time percentage alone.
Carrier by carrier
Which airline is most reliable on DFW to ONT
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Frontier Airlinesthin sample | 322 | 81.4% | 62 min | 2.80% | B |
| American Airlines | 1,984 | 66.9% | 66 min | 2.92% | C |
Departure window
The best time of day to leave
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 40 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am52 flights93.9%
- 8am–11am535 flights79.4%
- 11am–2pm489 flights76.9%
- 2pm–5pm164 flights72.5%
- 5pm–8pm464 flights63.7%
- 8pm–5am602 flights53.8%
Scale runs 45% to 100%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 53.8% on time, against 93.9% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 8pm–5am window is the busiest, with 602 flights scheduled in it.
Across the year
When delays peak on this route
This route's year swings by 37 points from best month to worst, which is wide. An annual average tells you very little about the week you are actually flying, so read the strip rather than the headline if your dates are fixed.
July is the worst month at 50.0% on time, 37 points below February, the best at 87.2%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. July was the busiest month here, with 224 flights.
Across the week, Tuesday is the strongest day at 74.1% on time and Sunday the weakest at 64.3%. 10 points is a smaller lever than departure hour, but it is free.
Delay causes
Why this route gets delayed
One category carries most of the weight here. Late-arriving aircraft accounts for 54% of the 46,000 delay minutes carriers reported, and the remaining four split what is left. The split is by minutes rather than by flights, so a few very long delays count for as much as many short ones.
- 54%Late-arriving aircraft
- 31%Carrier
- 8%National Airspace System
- 7%Extreme weather
- 0%Security
54% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 46,000 reported delay minutes here, that single category outweighs weather by 8 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 45,639 reported delay minutes.
The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 93.9% on time here.
Cancellations run at 2.91%, against 1.81% nationally. That is roughly one flight in 30 cancelled outright. A cancelled flight is invisible in every on-time figure on this page, so the punctuality numbers above describe only the flights that actually operated.
Connections and stage length
What a delay here actually costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 1,188 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 78.2% on time across 2,307 flights, 9 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 9 points of difference.
The sample behind these figures is 2,306 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking this route
Put together: the delay figures matter less here than the 2.91% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 5am–8am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 2,237 completed flights over 12 months sit behind that.
Common questions
DFW to ONT questions
How often is DFW to ONT delayed?
About one flight in three arrive at least 15 minutes late, which is the Department of Transportation's definition of a delayed arrival. That works out to 31.1% of the 2,306 flights in this analysis, against 22.4% nationally. Delayed flights are late by about an hour on average.
How reliable is DFW to ONT compared with the rest of the country?
68.9% of flights arrive on time here against a national 77.6%, a difference of 9 points against it. That is worth a C on this site's grading scale.
What time of day has the fewest delays on DFW to ONT?
The 5am–8am departure window is the strongest at 93.9% on time. The 8pm–5am window is the weakest at 53.8%, 40 points behind. Later departures inherit delays from earlier flights the same aircraft has already flown, which is why the curve slopes the way it does.
How bad are July delays on DFW to ONT?
July is the weakest month at 50.0% on time, compared with 87.2% in February. Across the year that is 37 points between the best and worst months. Moving flexible dates out of that month is one of the few things that reliably helps.
Related
Where to go next
- ONT to DFW — the return legseparate record
- Dallas/Fort Worth International (DFW) delay statistics
- Frontier Airlines on-time record81.4%
- American Airlines on-time record66.9%
- Why the first flight of the morning is statistically safest
- What a cancellation rate actually tells you (and what it hides)
Direction matters. DFW to ONT and ONT to DFW are scored separately because they are separate operations, with different departure banks and different aircraft. Compare the return leg.
Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Updated monthly. How this data is collected.