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Route · ONT → ATL · 2020–2025 BTS data

Ontario to Atlanta

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), ONT to ATL (Ontario to Atlanta) ranks #2515 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

88.6%
On-time
+9.6 pts
vs US avg
77 min
Delay when late
4,905
Flights
#2515 of 4927
Corpus placement

Cancelled

1.3%

Best Month

Jan 2024 98%

Worst Month

May 2024 84%

Distance

1,900 mi

Carriers

2

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 88 9 4 0 DL
Nov 2025 84 9 2 0 DL
Oct 2025 85 9 0 1 DL
Sep 2025 77 2 0 0 DL
Aug 2025 82 3 1 0 DL
Jul 2025 88 6 1 2 DL
Jun 2025 84 9 2 2 DL
May 2025 81 7 0 0 DL
Apr 2025 77 11 1 0 DL
Mar 2025 62 8 0 0 DL
Feb 2025 56 3 0 0 DL
Jan 2025 66 6 4 0 DL
Dec 2024 88 3 0 0 DL
Nov 2024 77 3 0 0 DL
Oct 2024 84 8 0 0 DL
Sep 2024 80 3 0 1 DL
Aug 2024 85 6 0 0 DL
Jul 2024 82 9 9 1 DL
Jun 2024 87 6 0 1 DL
May 2024 79 13 0 0 DL
Apr 2024 72 7 0 0 DL
Mar 2024 62 2 0 0 DL
Feb 2024 58 4 0 0 DL
Jan 2024 63 1 0 0 DL

ONT–ATL seasonal on-time pattern

Best: September (94.8%) · weakest: April (82.9%)

80%85%90%95%100% JanFebMarAprMayJunJulAugSepOctNovDec 87.5%

Strongest calendar month

September

94.8% on-time · ~67 flights/mo

Busiest calendar month

June

~83 flights/mo avg

Weakest calendar month

April

82.9% on-time · ~73 flights/mo

Cancellation Rate

1.3%

24 of 1,847 flights

Diversion Rate

0.4%

8 of 1,847 flights

Explore origin & destination

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

ONT - Ontario

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

ONT on-time profile

ATL - Atlanta

Full on-time, delay-cause, and seasonal performance for Atlanta, GA.

ATL on-time profile

Compare the two airports

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

Compare ONT vs ATL

Origin-hub reliability standing

Among ONT's stronger departures

ONT → ATL posts a 88.6% on-time rate, landing in the ≥85% band with 10 of 21 BTS-tracked routes leaving Ontario. The same hub also shows 9 mid-band and 2 challenged departures · fleet-wide on-time rank #316 of 4927 (highest on-time = #1).

What the Data Says About ONT to ATL

Ontario to Atlanta (ONT to ATL) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 88.6% on-time rate across 4,905 flights, with delays that do happen averaging 76.8 minutes. The corridor runs roughly 1,900 miles and is served by 2 carriers. Over the most recent 24 months, 24 of 1,847 flights were cancelled (1.3%) and 8 diverted (0.4%).

Monthly performance varies moderately here: Jan 2024 was the strongest month at 98% on-time versus May 2024 at 84%, a 15-point difference.

On the multi-year calendar, ONT–ATL peaks in September at 94.8% on-time while June carries the heaviest traffic (~83 flights per month) ; the softest month is April at 82.9%, a 11.9-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does ONT to ATL rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, ONT to ATL ranks #2515 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 ONT to ATL? ▼
Flights from Ontario to Atlanta have a 88.6% on-time rate based on 4,905 flights. The average delay is 76.8 minutes. The best recent month was Jan 2024 with 98% on-time.
What is the cancellation rate for ONT to ATL? ▼
Over the last 24 months, 1.3% of flights on this route were cancelled (24 of 1,847 flights) and 0.4% were diverted.
How far is the flight from ONT to ATL? ▼
The flight distance from Ontario (ONT) to Atlanta (ATL) is approximately 1,900 miles. This route is served by 2 carriers.
When is the best time to fly from ONT to ATL? ▼
The best recent month for on-time performance was Jan 2024 (98% on-time). The worst was May 2024 (84% on-time). Consider booking during months with historically better performance.

Airports on this route

ONT Airport

Ontario
ATL Airport

Atlanta
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 ONT–ATL data

ONT–ATL runs 9.6 pts above the national 79% average; the remaining risk is month-to-month swing and carrier mix, not a weak headline rate.

  • Compare ONT and ATL airport profiles: delay causes and top routes differ even on the same corridor. ONT airport
  • If your dates flex, September (94.8% on-time) beats April (82.9%) on this corridor. Seasonal chart
  • 4 other routes post a similar 88.6% 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.