Airport month record

MKESEP

Milwaukee Mitchell International in September 2025

Departures: 2,315
Month: September 2025
National, same month: 83.4%
Carriers: 8

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at MKE, see live FAA status.

MKE in September lands a B+, level with the national rate of 83.4%. About one flight in six arrives 15 minutes late or worse, and those flights are late by about an hour on average. That rests on 2,315 flights, of which Delta Air Lines flew 371 at 88.7% on time.

Delta Air Lines is the most reliable of the three carriers covered here at 88.7% on time across 371 flights.

On time

83.0%

Arrivals under 15 minutes late, of 2,297 completed departures

Avg delay

64 min

Across delayed arrivals only, not all flights

Cancelled

0.56%

Nationally in September: 0.51%

Whole year

78.1%

MKE across all twelve months

These figures cover 2,315 departures from Milwaukee Mitchell International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

September next to MKE's other months

Against MKE's own year, September ran 5 points better than the twelve-month rate of 78.1%, which makes it the best of the twelve months in the data. Cancellations were unusually low for MKE in September, at 0.56% against 2.41% across the year.

MKE month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
September 2025 (this page)	2,315	83.0%	64 min	0.56%	B+
October 2025	2,564	79.6%	79 min	0.31%	B+
November 2025	2,230	79.2%	81 min	4.26%	B−
December 2025	2,273	70.1%	92 min	1.89%	C
January 2026	2,077	73.8%	78 min	3.71%	C−
February 2026	2,033	82.7%	79 min	1.33%	B
March 2026	2,626	74.3%	98 min	6.25%	C−
April 2026	2,588	80.7%	86 min	2.20%	B
May 2026	2,735	80.6%	65 min	0.73%	B+
June 2026	2,657	79.2%	72 min	2.11%	B
July 2026	2,759	76.5%	82 min	2.97%	B
August 2026	2,715	77.2%	85 min	2.62%	B

Departure window

The best time of day to leave MKE in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 27 points, against 10 points between the best and worst carrier.

5am–8am620 flights91.9%
8am–11am389 flights88.9%
11am–2pm401 flights81.1%
2pm–5pm475 flights75.9%
5pm–8pm392 flights75.3%
8pm–5am38 flights64.9%

Scale runs 55% to 95%.

The 8pm–5am window is where this operation falls apart: 64.9% on time, against 91.9% 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 620 flights scheduled in it.

Across the week, Tuesday is the strongest day at 87.7% on time and Friday the weakest at 78.0%, a spread of 10 points.

Carrier by carrier

Which airlines ran best at MKE in September

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 88.7% of the time; SkyWest Airlines manages 78.9%. Sample sizes sit next to every figure, because a two-point gap across 540 flights means less than a ten-point one.

Carriers at MKE in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	719	87.1%	42 min	0.28%	A+
SkyWest Airlines	540	78.9%	76 min	0.56%	B+
Delta Air Lines	371	88.7%	50 min	0.00%	A+
Republic Airwaysthin sample	187	70.5%	69 min	2.14%	C
American Airlinesthin sample	176	85.0%	117 min	1.14%	A
PSA Airlinesthin sample	128	83.6%	83 min	0.00%	B+
United Airlinesthin sample	81	76.5%	47 min	0.00%	B+
Alaska Airlinesthin sample	60	84.7%	32 min	1.67%	B

Delta leads SkyWest by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of MKE in September

Routes from MKE in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
MKE to ORD · Chicago	394	74.1%	80 min	0.76%	C+
MKE to DEN · Denverthin sample	227	82.7%	44 min	0.44%	B+
MKE to ATL · Atlantathin sample	187	95.2%	46 min	0.00%	A+
MKE to MSP · Minneapolisthin sample	129	77.5%	45 min	0.00%	B+
MKE to DTW · Detroitthin sample	112	92.0%	49 min	0.00%	A+
MKE to DCA · Washingtonthin sample	112	83.0%	69 min	0.00%	B+
MKE to PHX · Phoenixthin sample	98	86.5%	48 min	1.02%	A
MKE to LAS · Las Vegasthin sample	93	80.4%	33 min	1.08%	B
MKE to DFW · Dallas-Fort Worththin sample	90	83.9%	100 min	2.22%	B
MKE to CLT · Charlottethin sample	89	85.4%	153 min	0.00%	A+
MKE to EWR · Newarkthin sample	83	76.2%	75 min	3.61%	B−
MKE to MCO · Orlandothin sample	79	87.2%	39 min	0.00%	A+
MKE to BOS · Bostonthin sample	78	46.8%	55 min	1.28%	F
MKE to BNA · Nashvillethin sample	77	94.8%	24 min	0.00%	A+
MKE to BWI · Baltimorethin sample	77	89.6%	56 min	0.00%	A+
MKE to STL · St. Louisthin sample	60	95.0%	24 min	0.00%	A+
MKE to SEA · Seattlethin sample	60	84.7%	32 min	1.67%	B
MKE to LGA · New Yorkthin sample	46	89.1%	117 min	0.00%	A+
MKE to PHL · Philadelphiathin sample	41	78.0%	61 min	0.00%	B+
MKE to DAL · Dallasthin sample	35	79.4%	61 min	0.00%	B+
MKE to MCI · Kansas Citythin sample	30	90.0%	24 min	0.00%	A+
MKE to TPA · Tampathin sample	30	100.0%	—	0.00%	A+
MKE to IAH · Houstonthin sample	30	100.0%	—	0.00%	A+

Delay causes

What held MKE up in September

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 25,000 reported delay minutes.

Carrier
42%
National Airspace System
25%
Late-arriving aircraft
23%
Extreme weather
10%

The largest share of delay minutes, 42%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 10,000 of the 25,000 delay minutes reported here. The split is drawn from 24,912 reported delay minutes.

Cancellations are rare at 0.56%, below the national 0.51% 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.

Badly late arrivals are rare here: only 4.8% land an hour or more behind schedule, against 5.4% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

What to do with this

Flying from MKE in September

For a September trip through MKE: this is one of the better months to be flying from here, 83.0% on time with 0.56% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

Milwaukee Mitchell International (MKE), the whole year
MKE in October79.6%
MKE in November79.2%
MKE in December70.1%
MKE in January73.8%
MKE in February82.7%
MKE in March74.3%
MKE in April80.7%
MKE in May80.6%
MKE in June79.2%
MKE in July76.5%
MKE in August77.2%

Source: US DOT Bureau of Transportation Statistics, on-time performance data, September 2025 to August 2026. Last updated 22 October 2026; recomputed monthly. How this data is collected.

Key figures