Carrier route record
YXBUF→ORD
Republic Airways · Buffalo to Chicago
- Flights
- 355
- Period
- July 2025 to June 2026
- Share of route
- 16%
- Carriers
- 5
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.
Republic on BUF to ORD lands a B−, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by an hour and a half on average. That is a workable record, not a spotless one. That rests on 355 flights. The strongest carrier on the route with a full sample, American Airlines, flew 476 at 84.0% on time.
American Airlines is the most reliable of the three carriers covered here at 84.0% on time across 476 flights.
Key figures
On time
76.2%
Arrivals under 15 minutes late, of 341 completed flights
Avg delay
95 min
Across delayed arrivals only, not all flights
Cancelled
3.66%
National rate is 1.81%
Whole route
74.0%
Every carrier on BUF to ORD, 2,196 flights
These figures cover 355 flights between July 2025 and June 2026. Beyond the headline rate, 12.6% 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 BUF to ORD
Republic flew 355 of the 2,196 flights on BUF to ORD, about 16% of it. Its 76.2% on time is 2 points better than the route as a whole, which runs 74.0%. Ranked by on-time rate it is number two of five carriers on the route, where the range runs from American at 84.0% to SkyWest at 60.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. American Airlines arrives on time 84.0% of the time; Envoy Air manages 70.8%. Sample sizes sit next to every figure, because a two-point gap across 423 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| American Airlines | 476 | 84.0% | 124 min | 1.47% | B |
| Republic Airways (this page)thin sample | 355 | 76.2% | 95 min | 3.66% | B− |
| United Airlines | 612 | 74.1% | 88 min | 1.47% | C |
| Envoy Air | 423 | 70.8% | 68 min | 3.31% | C− |
| SkyWest Airlinesthin sample | 330 | 60.2% | 134 min | 6.06% | D− |
Envoy Air cancels 3.3% 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 29 points, against 13 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am118 flights78.4%
- 8am–11am54 flights94.4%
- 11am–2pm50 flights78.7%
- 2pm–5pm1 flights—
- 5pm–8pm129 flights65.8%
- 8pm–5am3 flights—
Scale runs 55% to 100%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 94.4% of the time, against 65.8% for the evening window. That is 29 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 129 flights scheduled in it.
Across the year
Republic on BUF to ORD through the year
- Jul–Sep 202516 flights—
- Oct–Dec 202554 flights72.5%
- Jan–Mar 2026173 flights72.3%
- Apr–Jun 2026112 flights81.5%
Scale runs 65% to 85%. 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 76.2% on time across 355 flights.
Quarter by quarter Republic on BUF to ORD held fairly steady: 72.5% in Oct–Dec 2025, 72.3% in Jan–Mar 2026 and 81.5% in Apr–Jun 2026. A spread of 9 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.
Across the week, Thursday is the strongest day at 82.7% on time and Tuesday the weakest at 65.2%. 18 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Republic runs late on this route
Carriers report a reason for every delay minute they cause, in five DOT categories. The split below is by minutes, not by number of flights, so a handful of very long weather delays weighs as much as many short ones. It covers 7,693 reported delay minutes.
- 40%Late-arriving aircraft
- 29%National Airspace System
- 17%Carrier
- 15%Extreme weather
Extreme weather accounts for 15% of delay minutes, well above the single-digit share typical across the system. Weather delays are lumpy: they arrive as whole bad days rather than as a steady drag, so the monthly strip above is the more useful view of the risk. The national share is 6%, so this operation carries roughly 2.3 times the usual weather exposure. The split is drawn from 7,693 reported delay minutes.
40% 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 7,693 reported delay minutes here, that single category outweighs weather by 3 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.
Cancellations run at 3.66%, against 1.81% nationally. That is roughly 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. 12.6% 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 474 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 8am–11am window matters as much as it does.
The return leg runs 74.3% on time across 355 flights, within 2 points of this direction. The two legs are scored separately because they usually differ; on this city pair they happen not to.
One caution: this is a thin sample. 355 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 BUF to ORD
Put together: the delay figures matter less here than the 3.66% cancellation rate. A late arrival costs you an hour and a half; a cancelled flight costs you the day. Book the 8am–11am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 341 completed flights over 12 months sit behind that.
Related
Where to go next
- BUF to ORD, every carrier
- Republic on ORD to BUF, the return leg
- American Airlines on BUF to ORD84.0%
- United Airlines on BUF to ORD74.1%
- Envoy Air on BUF to ORD70.8%
- SkyWest Airlines on BUF to ORD60.2%
- Republic Airways network-wide record
- Chicago O'Hare International (ORD) delay statistics
- The US routes with the most cancellations
- Why the first flight of the morning is statistically safest
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.