Carrier route record
YXORD→BOS
Republic Airways · Chicago to Boston
- Flights
- 932
- Period
- September 2025 to August 2026
- Share of route
- 12%
- Carriers
- 6
Historical statistics for September 2025 to August 2026, not live status. For today’s flights, check with Republic Airways.
Republic on ORD to BOS carries a cancellation problem, not just a delay problem: 5.9% of scheduled flights never operate, against 1.9% nationally. Of the ones that do fly, about seven flights in ten arrive on time, worth a C− overall. The punctuality figure counts only flights that actually departed, so it flatters an operation that cancels this often. That rests on 932 flights. The strongest carrier on the route with a full sample, Envoy Air, flew 440 at 82.7% on time.
Envoy Air is the most reliable of the five carriers covered here at 82.7% on time across 440 flights.
Key figures
On time
69.7%
Arrivals under 15 minutes late, of 876 completed flights
Avg delay
79 min
Across delayed arrivals only, not all flights
Cancelled
5.90%
National rate is 1.89%
Whole route
66.6%
Every carrier on ORD to BOS, 7,864 flights
These figures cover 932 flights between September 2025 and August 2026. Beyond the headline rate, 12.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Carrier by carrier
Republic against every carrier on ORD to BOS
Republic flew 932 of the 7,864 flights on ORD to BOS, about 12% of it. Its 69.7% on time is 3 points better than the route as a whole, which runs 66.6%. Ranked by on-time rate it is number two of six carriers on the route, where the range runs from Envoy at 82.7% to American at 59.5%.
The choice of carrier is not cosmetic here. Envoy Air arrives on time 82.7% of the time; American Airlines manages 59.5%. Sample sizes sit next to every figure, because a two-point gap across 2,164 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Envoy Air | 440 | 82.7% | 67 min | 2.50% | B |
| Republic Airways (this page) | 932 | 69.7% | 79 min | 5.90% | C− |
| JetBlue Airways | 553 | 68.1% | 98 min | 3.98% | C− |
| United Airlines | 2,794 | 68.0% | 80 min | 1.79% | C |
| Delta Air Lines | 981 | 67.4% | 90 min | 3.47% | C− |
| American Airlines | 2,164 | 59.5% | 78 min | 2.91% | D |
JetBlue Airways cancels 4.0% 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.
Timetable by Aviasales, a Travelpayouts partner. Booking through it may earn this site a commission at no cost to you; it changes no figure here.
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 20 points, against 23 points between the best and worst carrier.
- 5am–8am308 flights79.7%
- 8am–11am88 flights72.3%
- 11am–2pm100 flights68.0%
- 2pm–5pm216 flights61.2%
- 5pm–8pm124 flights66.4%
- 8pm–5am96 flights59.3%
Scale runs 50% to 85%.
The 8pm–5am window is where this operation falls apart: 59.3% on time, against 79.7% for the 5am–8am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 5am–8am window is the busiest, with 308 flights scheduled in it.
Across the year
Republic on ORD to BOS through the year
June is the worst month at 54.3% on time, 34 points below May, the best at 87.8%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. January was the busiest month here, with 178 flights.
Across the week, Tuesday is the strongest day at 77.6% on time and Friday the weakest at 60.0%, a spread of 18 points.
Arrival by arrival
How late Republic on ORD to BOS runs when it is late
Republic on ORD to BOS often beats the schedule: 305 of 876 completed flights, 35%, arrived 15 minutes or more early. The 265 late arrivals split 79 under half an hour, 75 between 30 and 60 minutes, and 111 an hour or more.
- 15+ min early305 flights34.8%
- Within 15 min306 flights34.9%
- 15–29 min late79 flights9.0%
- 30–59 min late75 flights8.6%
- 1–2 hours late63 flights7.2%
- 2+ hours late48 flights5.5%
Scale runs 0% to 100%.
Share of 876 completed flights by arrival against schedule.
42 of 234 late departures made up the time and arrived on time, 18% of them. In the other direction, 73 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at BOS.
The worst days
Worst days for Republic on ORD to BOS
The latest arrival of the period was on 28 January 2026, 21 hours 53 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). On three of the five worst days the largest share was filed as a late-arriving aircraft.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 28 January 2026 | 21 hours 53 minutes | Carrier |
| 3 July 2026 | 14 hours 40 minutes | Late-arriving aircraft |
| 6 February 2026 | 9 hours 22 minutes | Extreme weather |
| 17 March 2026 | 7 hours 48 minutes | Late-arriving aircraft |
| 29 December 2025 | 4 hours 57 minutes | Late-arriving aircraft |
Delay causes
Why Republic runs late on this route
Late-arriving aircraft accounts for 44% of the 21,000 delay minutes carriers reported here, and the remaining four split what is left.
- 44%Late-arriving aircraft
- 25%National Airspace System
- 20%Carrier
- 11%Extreme weather
Extreme weather accounts for 11% 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 1.8 times the usual weather exposure. The split is drawn from 21,002 reported delay minutes.
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. Across 21,000 reported delay minutes here, that single category outweighs weather by 4 to one.
Cancellations run at 5.90%, against 1.89% nationally. That is roughly one flight in fifteen 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
12.7% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The 867 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
The return leg runs 71.2% on time across 930 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. 932 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 ORD to BOS
Put together: the delay figures matter less here than the 5.90% 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. 876 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to BOS, every carrier
- Republic on BOS to ORD, the return leg
- Envoy Air on ORD to BOS82.7%
- JetBlue Airways on ORD to BOS68.1%
- United Airlines on ORD to BOS68.0%
- Delta Air Lines on ORD to BOS67.4%
- American Airlines on ORD to BOS59.5%
- Republic Airways network-wide record
- Chicago O'Hare International (ORD) delay statistics
- Boston Logan International (BOS) delay statistics
- The US routes with the most cancellations
- Same route, different airline: where the carrier you pick matters most
Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.