Flight number record

OO 4803

SkyWest Airlines · Milwaukee to Chicago

Route: MKE → ORD
Departs: 07:00
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 4803, check with SkyWest Airlines. SkyWest Airlines flies under contract for larger airlines, so a ticket for this flight may show a different airline code and number.

OO 4803 lands a B, about a point 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 2.4 hours on average. That is a workable record, not a spotless one. That rests on 363 flights, with a median arrival 7 minutes early.

On time

78.5%

Arrivals under 15 minutes late, of 354 completed flights

Avg delay

146 min

Across delayed arrivals only, not all flights

Cancelled

2.48%

National rate is 1.81%

1 hour+ late

13.3%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. Beyond the headline rate, 13.3% 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.

Schedule

When OO 4803 flies

OO 4803 flies MKE to ORD without a single fixed slot. Its most common scheduled departure was 07:00, used on 250 of 363 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 07:00250 flights68.9%

Scale runs 0% to 100%. Rows with fewer than 30 flights show a dash.

Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.

A 07:00 departure sits in the 5am–8am window. Across every US flight scheduled in that window the on-time rate is 89.3%, and OO 4803 runs 11 points worse at 78.5%. Early departures usually start with an aircraft that has not flown yet that day, which is most of why the window does well.

Against the route

OO 4803 next to MKE to ORD

Every carrier on MKE to ORD combined arrived on time 67.4% of the time across 5,202 flights, so OO 4803 is 11 points ahead of it. SkyWest flew 4,932 flights on the same city pair under all its flight numbers, including this one, and those ran 67.3% on time. Across its whole network SkyWest Airlines managed 79.0%, close to this flight's figure.

OO 4803 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 4803thin sample	363	78.5%	146 min	2.48%	B
All SkyWest Airlines on MKE–ORD	4,932	67.3%	94 min	4.12%	C−
All carriers on MKE–ORD	5,202	67.4%	94 min	4.33%	C−
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 4803 quarter by quarter

Quarter by quarter OO 4803 held fairly steady: 77.8% in Jul–Sep 2025, 77.8% in Oct–Dec 2025, 75.6% in Jan–Mar 2026 and 83.0% in Apr–Jun 2026. A spread of 7 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights77.8%
Oct–Dec 202591 flights77.8%
Jan–Mar 202689 flights75.6%
Apr–Jun 202691 flights83.0%

Scale runs 65% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, OO 4803 did best on Thursday at 86.0% on time and worst on Tuesday at 71.2%. Each day rests on about 52 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 4803 runs late

One category carries most of the weight here. Carrier accounts for 67% of the 11,000 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.

Carrier
67%
Late-arriving aircraft
16%
National Airspace System
9%
Extreme weather
8%

The largest share of delay minutes, 67%, 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 7,463 of the 11,000 delay minutes reported here. The split is drawn from 11,130 delay minutes reported on OO 4803.

Cancellations sit at 2.48% against a national 1.81%, which is ordinary. Diversions add another 0.00%.

Connections and routes

What a delay on this flight costs

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 13.3% 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.

Every one of the 363 flights under OO 4803 in the data flew MKE to ORD. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 363 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 OO 4803

For a booking, OO 4803 is a flight to put a long connection behind. 13.3% of its completed flights arrived an hour or more late, which a short layover will not absorb. If the onward flight is on a separate ticket, the risk sits with you.

Where to go next

A flight number here means SkyWest Airlines’s own number as it reports to the DOT. How the figures are computed is on the methodology page.

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