PlainFlights

Route · DEN → ONT · 2020–2025 BTS data

Denver to Ontario

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), DEN to ONT (Denver to Ontario) ranks #672 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

75.1%
On-time
-3.9 pts
vs US avg
58 min
Delay when late
14,378
Flights
#672 of 4927
Corpus placement

Cancelled

0.6%

Best Month

Oct 2024 89%

Worst Month

Jul 2025 59%

Distance

819 mi

Carriers

13

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 194 60 0 0 WN,F9,UA
Nov 2025 220 36 1 0 UA,F9,WN
Oct 2025 242 63 1 0 UA,WN,F9
Sep 2025 236 57 0 0 UA,WN,F9
Aug 2025 254 74 0 0 WN,F9,UA
Jul 2025 272 112 2 0 UA,WN,F9
Jun 2025 261 104 4 0 UA,WN,F9
May 2025 260 66 4 0 OO,UA,WN,F9
Apr 2025 252 59 4 0 F9,OO,UA,WN
Mar 2025 217 38 0 0 UA,WN,F9
Feb 2025 187 46 0 0 UA,WN,F9
Jan 2025 209 48 1 4 UA,WN,F9
Dec 2024 223 32 0 0 F9,UA,WN
Nov 2024 224 56 1 1 UA,WN,F9
Oct 2024 259 28 0 0 UA,WN,F9
Sep 2024 249 47 0 0 WN,UA,F9
Aug 2024 263 75 1 0 F9,WN,UA
Jul 2024 273 75 4 0 F9,UA,WN
Jun 2024 264 87 1 0 F9,UA,WN
May 2024 247 68 0 0 F9,UA,WN
Apr 2024 232 42 0 0 F9,UA,WN
Mar 2024 237 54 4 0 F9,UA,WN
Feb 2024 219 61 1 0 F9,UA,WN
Jan 2024 229 59 3 0 F9,WN,UA

DEN–ONT seasonal on-time pattern

Best: November (80.2%) · weakest: June (66.5%)

65%70%75%80%85% JanFebMarAprMayJunJulAugSepOctNovDec 74.1%

Strongest calendar month

November

80.2% on-time · ~202 flights/mo

Busiest calendar month

August

~233 flights/mo avg

Weakest calendar month

June

66.5% on-time · ~206 flights/mo

Cancellation Rate

0.6%

32 of 5,723 flights

Diversion Rate

0.1%

5 of 5,723 flights

Explore origin & destination

On-time and delay data for the airports this route connects.

DEN - Denver

Full on-time, delay-cause, and seasonal performance for Denver, CO.

DEN on-time profile

ONT - Ontario

Full on-time, delay-cause, and seasonal performance for Ontario, CA.

ONT on-time profile

Compare the two airports

See DEN and ONT side by side on delays, cancellations, and reliability.

Compare DEN vs ONT

Origin-hub reliability standing

Mid-pack among DEN departures

From DEN, this corridor sits with 133 other 75–85% on-time routes out of 168 tracked departures, not the hub's reliability leaders (8 at ≥85%) and not the softest ( 27 below 75%). Destination: Ontario · fleet on-time rank #4450 of 4927.

What the Data Says About DEN to ONT

The Denver to Ontario corridor (DEN to ONT) posts a 75.1% on-time rate on the lower edge of the average band, based on 14,378 tracked flights. Late flights run 58.2 minutes behind on average. 13 carriers cover the 819-mile route; over the last 24 months, 32 of 5,723 flights were cancelled (0.6%) and 0.1% diverted.

The monthly split is wide on this route: Oct 2024 posted the strongest performance at 89% on-time, while Jul 2025 came in at just 59% - a 30-point swing worth factoring into travel timing.

On the multi-year calendar, DEN–ONT peaks in November at 80.2% on-time while August carries the heaviest traffic (~233 flights per month) ; the softest month is June at 66.5%, a 13.7-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does DEN to ONT rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, DEN to ONT ranks #672 of 4927 tracked domestic routes by total flights (most flights = #1). That ordinal matches our busiest-routes listing (total_flights DESC). See /methodology#corpus-placement for the exact sort basis.
How often are flights delayed from DEN to ONT? ▼
Flights from Denver to Ontario have a 75.1% on-time rate based on 14,378 flights. The average delay is 58.2 minutes. The best recent month was Oct 2024 with 89% on-time.
What is the cancellation rate for DEN to ONT? ▼
Over the last 24 months, 0.6% of flights on this route were cancelled (32 of 5,723 flights) and 0.1% were diverted.
How far is the flight from DEN to ONT? ▼
The flight distance from Denver (DEN) to Ontario (ONT) is approximately 819 miles. This route is served by 13 carriers.
When is the best time to fly from DEN to ONT? ▼
The best recent month for on-time performance was Oct 2024 (89% on-time). The worst was Jul 2025 (59% on-time). Consider booking during months with historically better performance.

Airports on this route

DEN Airport

Denver
ONT Airport

Ontario
Data source

Data Source: Bureau of Transportation Statistics (BTS), On-Time Performance Data. Statistics reflect cumulative performance across all available reporting periods.

Read our methodology - how this data is sourced, computed, and verified.

Using DEN–ONT data

DEN–ONT is mid-pack at 75.1% on-time; month and carrier mix move more than the corridor headline.

  • Compare DEN and ONT airport profiles: delay causes and top routes differ even on the same corridor. DEN airport
  • If your dates flex, November (80.2% on-time) beats June (66.5%) on this corridor. Seasonal chart
  • 4 other routes post a similar 75.1% on-time rate; compare before you commit to this pairing. Similar routes

On-time rate reflects the BTS historical average across all reporting carriers on this origin–destination pair, not any single flight or booking recommendation.

Data sourced from U.S. Department of Transportation Bureau of Transportation Statistics (BTS) On-Time Performance data. See our methodology for details. Retrieved and formatted by PlainFlights

Every figure on PlainFlights is rendered directly from BTS On-Time Performance data, no number is typed in by an editor. This page aggregates this specific route's on-time performance and monthly trend, live from the dataset. See our editorial standards & corrections policy, the methodology behind these numbers, or report a data error.