Carrier route record

YXSTL→ORD

Republic Airways · St. Louis to Chicago

Flights: 448
Period: July 2025 to June 2026
Share of route: 15%
Carriers: 5

Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.

Republic on STL to ORD sits in the middle of the pack with a C−. About seven flights in ten arrive on time by the DOT's definition, 6 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 448 flights. The strongest carrier on the route with a full sample, American Airlines, flew 533 at 80.7% on time.

American Airlines is the most reliable of the four carriers covered here at 80.7% on time across 533 flights.

On time

72.0%

Arrivals under 15 minutes late, of 429 completed flights

Avg delay

76 min

Across delayed arrivals only, not all flights

Cancelled

4.02%

National rate is 1.81%

Whole route

71.1%

Every carrier on STL to ORD, 3,070 flights

These figures cover 448 flights between July 2025 and June 2026. Beyond the headline rate, 11.2% 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

Republic against every carrier on STL to ORD

Republic flew 448 of the 3,070 flights on STL to ORD, about 15% of it. Its 72.0% on time is about level with the route as a whole at 71.1%. Ranked by on-time rate it is number three of five carriers on the route, where the range runs from American at 80.7% to SkyWest at 62.8%.

The choice of carrier is not cosmetic here. American Airlines arrives on time 80.7% of the time; SkyWest Airlines manages 62.8%. Sample sizes sit next to every figure, because a two-point gap across 836 flights means less than a ten-point one.

On-time performance by carrier on STL to ORD
Airline	Flights	On time	Avg delay	Cancelled	Grade
American Airlines	533	80.7%	126 min	2.44%	B
Envoy Air	728	74.6%	93 min	2.61%	C
Republic Airways (this page)	448	72.0%	76 min	4.02%	C−
United Airlines	525	68.6%	85 min	1.52%	C
SkyWest Airlines	836	62.8%	104 min	4.90%	D−

SkyWest Airlines cancels 4.9% of what it schedules here, the highest in the table. A cancelled flight never appears in an on-time rate, so read that column alongside the punctuality one rather than after it.

Departure window

When Republic runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 17 points, against 18 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am54 flights83.3%
8am–11am52 flights75.5%
11am–2pm12 flights—
2pm–5pm178 flights71.6%
5pm–8pm149 flights66.2%
8pm–5am3 flights—

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 83.3% of the time, against 66.2% for the evening window. That is 17 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 2pm–5pm window is the busiest, with 178 flights scheduled in it.

Across the year

Republic on STL to ORD through the year

Jul–Sep 202575 flights63.4%
Oct–Dec 2025225 flights70.2%
Jan–Mar 202668 flights85.7%
Apr–Jun 202680 flights74.0%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

Monthly volumes are too low here to break the year into twelve reliable readings. What the twelve-month total says is 72.0% on time across 448 flights.

Republic on STL to ORD did not run the same all year. Its best quarter was Jan–Mar 2026 at 85.7% on time and its weakest Jul–Sep 2025 at 63.4%, a swing of 22 points on roughly 112 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.

Across the week, Saturday is the strongest day at 82.5% on time and Sunday the weakest at 57.4%. 25 points is a smaller lever than departure hour, but it is free.

Delay causes

Why Republic runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 52% of the 9,132 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.

Late-arriving aircraft
52%
National Airspace System
33%
Carrier
15%
Extreme weather
1%

52% 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 9,132 reported delay minutes here, that single category outweighs weather by 52 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 9,132 reported delay minutes.

33% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 3,020 minutes out of 9,132, against a national NAS share of 21%.

Cancellations run at 4.02%, against 1.81% nationally. That is about one flight in 25 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 costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.2% 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.

At 258 miles this is a short hop, and stage length matters more than it looks. A flight this short spends under two hours in the air, which leaves almost nothing to claw back a late pushback with. Delay here is decided on the ground, in the turn, which is why the 5am–8am window matters as much as it does.

The return leg is a different operation and performs like one: it runs 76.2% on time across 444 flights, 4 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 4 points of difference.

One caution: this is a thin sample. 448 flights over twelve months is enough to clear this site's floor but not enough to pin the rate down tightly, and a single bad week moves it by more than a point. Treat the grade as a rough reading.

What to do with this

Booking Republic on STL to ORD

Put together: the delay figures matter less here than the 4.02% cancellation rate. A late arrival costs you a little over 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. 429 completed flights over 12 months sit behind that.

Where to go next

Source: US DOT Bureau of Transportation Statistics, on-time performance data, July 2025 to June 2026. Last updated 15 September 2026; recomputed monthly. How this data is collected.

Key figures