Carrier route record
YXBOS→MKE
Republic Airways · Boston to Milwaukee
- Flights
- 549
- Period
- July 2025 to June 2026
- Share of route
- 74%
- Carriers
- 3
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Republic Airways.
Republic on BOS to MKE lands a B−, 3 points better than the national rate of 77.6%. About one flight in five arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 549 flights, with a median arrival 9 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Republic on BOS to MKE from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
80.8%
Arrivals under 15 minutes late, of 526 completed flights
Avg delay
59 min
Across delayed arrivals only, not all flights
Cancelled
4.01%
National rate is 1.81%
Whole route
80.5%
Every carrier on BOS to MKE, 742 flights
These figures cover 549 flights between July 2025 and June 2026. The median arrival is 9 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.
Carrier by carrier
Republic against every carrier on BOS to MKE
Republic flew 549 of the 742 flights on BOS to MKE, most of the route. Its 80.8% on time is about level with the route as a whole at 80.5%. Ranked by on-time rate it is number two of three carriers on the route, where the range runs from JetBlue at 83.0% to Delta at 50.0%. Two of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| JetBlue Airwaysthin sample | 172 | 83.0% | 68 min | 0.58% | B+ |
| Republic Airways (this page) | 549 | 80.8% | 59 min | 4.01% | B− |
| Delta Air Linesthin sample | 21 | 50.0% | 92 min | 4.76% | F− |
Flight by flight
Republic flight numbers on BOS to MKE
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 24 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am244 flights86.6%
- 11am–2pm18 flights—
- 2pm–5pm116 flights79.6%
- 5pm–8pm121 flights64.7%
- 8pm–5am50 flights88.9%
Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.
The 5pm–8pm window is where this operation falls apart: 64.7% on time, against 88.9% for the 8pm–5am 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 8am–11am window is the busiest, with 244 flights scheduled in it.
Across the year
Republic on BOS to MKE through the year
Delays peak in September, when the on-time rate falls to 61.8%. June is the strongest month at 95.7%. Moving a flexible trip across that boundary buys 34 points. October was the busiest month here, with 57 flights.
Across the week, Saturday is the strongest day at 95.6% on time and Friday the weakest at 73.8%. 22 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 5,970 reported delay minutes.
- 40%Carrier
- 36%Late-arriving aircraft
- 24%National Airspace System
- 0%Extreme weather
36% 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 5,970 reported delay minutes here, that single category outweighs weather by 36 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 5,970 reported delay minutes.
The largest share of delay minutes, 40%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. Unlike weather, that is a management outcome, and it is the category where the gap between two carriers on the same schedule is genuinely earned. It accounts for 2,391 of the 5,970 delay minutes reported here.
Cancellations run at 4.01%, 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
6.8% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.
The 860 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
The return leg is a different operation and performs like one: it runs 73.1% on time across 549 flights, 8 points below 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 8 points of difference.
One caution: this is a thin sample. 549 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 BOS to MKE
Put together: the delay figures matter less here than the 4.01% cancellation rate. A late arrival costs you about an hour; a cancelled flight costs you the day. Book the 8pm–5am departure so there is still a schedule behind you if it goes wrong, and treat a same-day connection as optimistic. 526 completed flights over 12 months sit behind that.
Related
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.