Carrier route record

B6BOS→MKE

JetBlue Airways · Boston to Milwaukee

Flights: 172
Period: July 2025 to June 2026
Share of route: 23%
Carriers: 3

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

JetBlue on BOS to MKE lands a B+, 5 points better than the national rate of 77.6%. About one flight in six 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 172 flights, with a median arrival 4 minutes early.

Set against the rest of the country, JetBlue's BOS to MKE record is 5 points better than the US average of 77.6%. That gap is worth roughly 54 fewer late arrivals for every thousand flights.

On time

83.0%

Arrivals under 15 minutes late, of 171 completed flights

Avg delay

68 min

Across delayed arrivals only, not all flights

Cancelled

0.58%

National rate is 1.81%

Whole route

80.5%

Every carrier on BOS to MKE, 742 flights

These figures cover 172 flights between July 2025 and June 2026. Beyond the headline rate, 8.2% 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

JetBlue against every carrier on BOS to MKE

JetBlue flew 172 of the 742 flights on BOS to MKE, about 23% of it. Its 83.0% on time is 3 points better than the route as a whole, which runs 80.5%. Ranked by on-time rate it is first of three carriers on the route, where the range runs from JetBlue at 83.0% to Delta at 50.0%. One 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.

On-time performance by carrier on BOS to MKE
Airline	Flights	On time	Avg delay	Cancelled	Grade
JetBlue Airways (this page)thin sample	172	83.0%	68 min	0.58%	B+
Republic Airways	549	80.8%	59 min	4.01%	B−
Delta Air Linesthin sample	21	50.0%	92 min	4.76%	F−

Departure window

When JetBlue runs best on this route

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 13 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–8am41 flights92.7%
8am–11am—
11am–2pm51 flights80.0%
2pm–5pm80 flights80.0%
5pm–8pm—
8pm–5am—

Scale runs 70% to 100%. Rows with fewer than 30 flights show a dash.

The weak window here is the middle of the day, not the evening: 11am–2pm runs 80.0% on time against 92.7% for 5am–8am. That shape usually means a departure bank rather than an accumulating delay, so the recovery later in the afternoon is real rather than noise. The 2pm–5pm window is the busiest, with 80 flights scheduled in it.

Across the year

JetBlue on BOS to MKE through the year

Jul–Sep 202584 flights78.3%
Oct–Dec 202525 flights—
Apr–Jun 202663 flights85.7%

Scale runs 70% 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 83.0% on time across 172 flights.

Split by quarter, JetBlue on BOS to MKE logged 84 flights in Jul–Sep 2025, 25 flights in Oct–Dec 2025 and 63 flights in Apr–Jun 2026. Fewer than three of those quarters carried the 30 completed flights this site needs before printing a rate, so the 83.0% annual figure is the one to use.

Delay causes

Why JetBlue runs late on this route

One category carries most of the weight here. Late-arriving aircraft accounts for 50% of the 1,960 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
50%
Carrier
32%
National Airspace System
18%

50% 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 1,960 reported delay minutes here, that single category outweighs weather by 50 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 1,960 reported delay minutes.

The practical consequence: the 5am–8am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 92.7% on time here.

Cancellations are rare at 0.58%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and stage length

What a delay here costs

8.2% 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 60.6% on time across 172 flights, 22 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 22 points of difference.

One caution: this is a thin sample. 172 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 JetBlue on BOS to MKE

Put together: treat all of this as provisional. 172 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 83.0% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 171 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