Routes › Chicago (ORD) › ORD to STL
Route · 12 months to July 2026
Chicago to St. Louis: on-time record
Chicago O'Hare International to St Louis Lambert International
BTS: A flight is counted as on time if it arrived less than 15 minutes after its scheduled time. Only carriers with at least 0.5 percent of domestic scheduled passenger revenue report. Data through July 2026; this is a monthly history, not live flight status.
69.8% of scheduled ORD to STL flights arrived on time in the 12 months to July 2026. The figure covers 3,090 flights between Chicago and St. Louis by carriers that report to BTS, a distance of 258 miles.
That is 6.2 points below the national on-time share of 76.0% for the same period and level with the 69.4% recorded for all departures from ORD. Flights that did arrive were 14.2 min late on average, and 2.9% of scheduled flights were cancelled (national: 1.8%).
5 reporting carriers flew the route at least 60 times. Republic Airline had the highest on-time share at 74.0% of 434 flights; American Airlines had the lowest at 64.2% of 505.
By scheduled departure hour (local time at ORD), flights leaving from 7 am to 8 am had the highest on-time share, 85.5%; those leaving from 5 pm to 6 pm had the lowest, 52.8%.
The on-time share is down 7.7 points on the previous 12 months (77.5%); cancellations moved from 0.9% to 2.9%.
Of the delay minutes that carriers assigned to a BTS cause category on this route, late-arriving aircraft 45%, air carrier 32% and national aviation system 14%.
- On time 69.8%
- Arrived 15+ minutes late 27.1%
- Cancelled 2.9%
- Diverted 0.2%
Airlines on the route compared
| Reporting carrier | Flights | Share | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| OO SkyWest Airlines | 809 | 26% | 66.3% | 16.4 min | 4.3% |
| MQ Envoy Air | 782 | 25% | 73.3% | 5.2 min | 2.7% |
| UA United Airlines | 560 | 18% | 72.0% | 15.5 min | 1.4% |
| AA American Airlines | 505 | 16% | 64.2% | 25.7 min | 2.8% |
| YX Republic Airline | 434 | 14% | 74.0% | 11.5 min | 3.0% |
Carriers with at least 24 flights in the 12 months to July 2026. The on-time pill is green when a carrier is at or above the route's overall share. Regional carriers operate flights sold under larger airlines' brands; BTS lists the carrier that operated the flight.
Compared with the airports and the nation
| Measure | ORD to STL | All departures from ORD | All arrivals at STL | All reported flights |
|---|---|---|---|---|
| Arrived on time | 69.8% | 69.4% | 77.7% | 76.0% |
| Arrived 15+ minutes late | 27.1% | 27.5% | 20.8% | 21.9% |
| Cancelled | 2.9% | 2.8% | 1.3% | 1.8% |
| Diverted | 0.2% | 0.3% | 0.2% | 0.3% |
| Average arrival delay | 14.2 min | 15.0 min | 5.6 min | 8.1 min |
| Delay minutes per 100 flights | 2,063 | 2,252 | 1,383 | 1,684 |
| Scheduled flights | 3,090 | 359,911 | 63,316 | 7,043,858 |
12 months to July 2026. Delay minutes count late arrivals only (an early arrival is zero), so the per-100-flights row is a normalised total rather than an average of early and late.
The return direction, STL to ORD, recorded 69.9% on time across 3,090 flights in the same period.
Month by month
Year on year: on time 69.8% against 77.5% (−7.7 pts), cancelled 2.9% against 0.9%, flights 3,090 against 2,775.
By scheduled departure hour
Delay causes
Seasonality
| Calendar month | Flights | On time | Cancelled | Avg arrival delay | Years in sample |
|---|---|---|---|---|---|
| Jan | 478 | 67.2% | 6.7% | 10.6 min | 3 |
| Feb | 514 | 78.6% | 0.6% | 8.9 min | 3 |
| Mar | 703 | 72.0% | 3.6% | 12.1 min | 3 |
| Apr | 816 | 75.6% | 2.1% | 7.6 min | 3 |
| May | 854 | 76.1% | 1.1% | 10.0 min | 3 |
| Jun | 831 | 71.0% | 1.6% | 14.1 min | 3 |
| Jul | 836 | 66.0% | 1.9% | 20.4 min | 3 |
| Aug | 718 | 72.8% | 1.3% | 15.0 min | 3 |
| Sep | 630 | 81.9% | 0.6% | 3.1 min | 3 |
| Oct | 656 | 80.9% | 0.0% | 4.8 min | 3 |
| Nov | 582 | 79.0% | 1.9% | 9.7 min | 3 |
| Dec | 546 | 73.4% | 1.6% | 13.6 min | 3 |
Each calendar month summed across the 36 months on file, so most rows combine three years. The pill compares the month with the route's own 12-month share.
Other routes from Chicago (ORD)
| Route | Cities | Flights | On time | Avg arrival delay | Cancelled |
|---|---|---|---|---|---|
| ORD–LGA | Chicago to New York | 11,611 | 63.5% | 19.6 min | 5.1% |
| ORD–BOS | Chicago to Boston | 7,755 | 65.6% | 18.3 min | 3.0% |
| ORD–DCA | Chicago to Washington | 7,042 | 67.5% | 17.5 min | 3.0% |
| ORD–LAX | Chicago to Los Angeles | 7,023 | 71.9% | 12.5 min | 1.4% |
| ORD–DFW | Chicago to Dallas/Fort Worth | 6,997 | 67.8% | 17.2 min | 2.9% |
| ORD–ATL | Chicago to Atlanta | 6,442 | 73.4% | 11.2 min | 2.3% |
| ORD–MSP | Chicago to Minneapolis | 6,344 | 68.3% | 17.8 min | 2.6% |
| ORD–MCO | Chicago to Orlando | 6,272 | 71.4% | 12.8 min | 1.6% |
All 193 routes and the airport record for ORD · airport record for STL
Questions and answers
How often are flights from Chicago to St. Louis on time?
69.8% of the 3,090 flights scheduled from ORD to STL in the 12 months to July 2026 arrived less than 15 minutes after their scheduled time. The national share for the same period was 76.0%. Cancelled and diverted flights count as not on time.
Which airline has the highest on-time share from ORD to STL?
Among reporting carriers with at least 60 flights on the route, Republic Airline had the highest on-time share (74.0%), followed by Envoy Air (73.3%) and United Airlines (72.0%). Differences of a point or two on a few hundred flights are small.
What causes delays between Chicago and St. Louis?
For flights that arrived 15 or more minutes late, carriers attributed the delay minutes as follows: late-arriving aircraft 45%, air carrier 32%, national aviation system 14%, extreme weather 10%, security 0%. The categories are the carriers' own reports to BTS; weather that slows the wider system is usually recorded under the National Aviation System rather than extreme weather.
What time of day has the highest on-time share from ORD?
Flights scheduled to leave ORD from 7 am to 8 am arrived on time 85.5% of the time, the highest of any hour with enough flights to compare. The lowest was 5 pm to 6 pm at 52.8%. Delays tend to build through the day as late aircraft carry over to later flights.
Is it getting better?
The on-time share for the 12 months to July 2026 was 69.8%, down 7.7 points on the previous 12 months (77.5%). The monthly chart on this page shows each of the last 36 months. Across those months, September had the highest on-time share (81.9%) and July the lowest (66.0%).
Where does this data come from?
Every figure is computed from the Bureau of Transportation Statistics Reporting Carrier On-Time Performance files, which list each scheduled domestic flight by the carriers required to report. This page covers August 2023 to July 2026. It shows totals and averages only; it is not a live flight-status service.
Provenance
Source: Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987 to present), monthly files August 2023 to July 2026, a US government work in the public domain. Figures are totals and averages over all scheduled flights by reporting carriers on the route; no individual flight or aircraft is identified. Times are local to the departure airport. The load factor and passenger counts from the BTS T-100 series are not included in this edition. See the methodology; report processing errors through corrections.