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Route · ONT → MDW · 2020–2025 BTS data

Ontario to Chicago

According to PlainFlights' route traffic ranking (BTS On-Time Performance total flights), ONT to MDW (Ontario to Chicago) ranks #4178 of 4927 tracked domestic routes by total flights (most flights = #1).

Data updated 2026-06-13

87.5%
On-time
+8.5 pts
vs US avg
57 min
Delay when late
1,463
Flights
#4178 of 4927
Corpus placement

Cancelled

0.4%

Best Month

N/A

Worst Month

N/A

Distance

1,706 mi

Carriers

4

Monthly Performance

Recent 24 months of route data.

Period Flights Delayed Cancelled Diverted Carriers
Dec 2025 31 4 0 0 WN
Nov 2025 30 3 1 0 WN
Oct 2025 31 0 0 0 WN
Sep 2025 30 1 0 0 WN
Aug 2025 31 2 0 1 WN
Jul 2025 31 5 0 0 WN
Jun 2025 30 5 0 0 WN
May 2025 31 1 0 0 WN
Apr 2025 30 0 0 0 WN
Mar 2025 31 2 0 0 WN
Oct 2024 31 4 0 1 WN
Sep 2024 34 6 0 0 WN
Aug 2024 34 4 0 0 WN
Jul 2024 31 2 0 0 WN
Jun 2024 30 2 0 0 WN
May 2024 31 3 0 1 WN
Apr 2024 30 2 0 0 WN
Mar 2024 31 1 0 0 WN
Jan 2024 31 4 2 0 WN
Dec 2023 31 5 0 0 WN
Sep 2023 30 3 0 0 WN
Aug 2023 31 4 0 0 WN
Jul 2023 31 9 0 1 WN
Jun 2023 30 7 0 0 WN

ONT–MDW seasonal on-time pattern

Best: March (96.7%) · weakest: July (82.8%)

80%85%90%95%100% JanMarAprMayJunJulAugSepOctNovDec 83.2%

Strongest calendar month

March

96.7% on-time · ~31 flights/mo

Busiest calendar month

December

~39 flights/mo avg

Weakest calendar month

July

82.8% on-time · ~31 flights/mo

Cancellation Rate

0.4%

3 of 742 flights

Diversion Rate

0.5%

4 of 742 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

MDW - Chicago

Full on-time, delay-cause, and seasonal performance for Chicago, IL.

MDW on-time profile

Compare the two airports

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

Compare ONT vs MDW

Origin-hub reliability standing

Among ONT's stronger departures

ONT → MDW posts a 87.5% 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 #517 of 4927 (highest on-time = #1).

What the Data Says About ONT to MDW

Ontario to Chicago (ONT to MDW) is one of the more dependable pairings in the BTS On-Time Performance dataset: a 87.5% on-time rate across 1,463 flights, with delays that do happen averaging 56.6 minutes. The corridor runs roughly 1,706 miles and is served by 4 carriers. Over the most recent 24 months, 3 of 742 flights were cancelled (0.4%) and 4 diverted (0.5%).

Monthly performance data for this route did not show a clear best/worst split in the sample window; review the monthly table above for period-by-period detail.

On the multi-year calendar, ONT–MDW peaks in March at 96.7% on-time while December carries the heaviest traffic (~39 flights per month) ; the softest month is July at 82.8%, a 13.9-point swing that repeats because the corridor's weather and holiday mix stays stable year to year.

Frequently Asked Questions

Where does ONT to MDW rank among US routes by traffic? ▼
According to PlainFlights' route traffic ranking, ONT to MDW ranks #4178 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 MDW? ▼
Flights from Ontario to Chicago have a 87.5% on-time rate based on 1,463 flights. The average delay is 56.6 minutes.
What is the cancellation rate for ONT to MDW? ▼
Over the last 24 months, 0.4% of flights on this route were cancelled (3 of 742 flights) and 0.5% were diverted.
How far is the flight from ONT to MDW? ▼
The flight distance from Ontario (ONT) to Chicago (MDW) is approximately 1,706 miles. This route is served by 4 carriers.

Airports on this route

ONT Airport

Ontario
MDW Airport

Chicago
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–MDW data

ONT–MDW runs 8.5 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 MDW airport profiles: delay causes and top routes differ even on the same corridor. ONT airport
  • If your dates flex, March (96.7% on-time) beats July (82.8%) on this corridor. Seasonal chart
  • 4 other routes post a similar 87.5% 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.