Flight number record

OO 5603

SkyWest Airlines · Chicago to Flint

Route: ORD → FNT
Departs: 20:08
Flights: 300
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 5603, 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 5603 draws a C−. About one flight in three arrives at least 15 minutes late, and the typical late arrival is close to two hours behind schedule. Build slack into anything you connect to. That rests on 300 flights, with a median arrival 3 minutes early.

The national on-time rate over the same period is 77.6%, so OO 5603 runs 11 points behind the country as a whole. Across a thousand flights that is about 114 extra late arrivals.

On time

66.2%

Arrivals under 15 minutes late, of 290 completed flights

Avg delay

102 min

Across delayed arrivals only, not all flights

Cancelled

3.33%

National rate is 1.81%

1 hour+ late

18.3%

National rate is 8.1%

These figures cover 300 flights between July 2025 and June 2026. Beyond the headline rate, 18.3% 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 5603 flies

OO 5603 flies ORD to FNT without a single fixed slot. Its most common scheduled departure was 20:08, used on 96 of 300 flights, with 20:03 (85 flights) and 20:10 (46 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 20:0896 flights32.0%
Departs 20:0385 flights28.3%
Departs 20:1046 flights15.3%

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 20:08 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and OO 5603 runs 4 points worse at 66.2%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.

Against the route

OO 5603 next to ORD to FNT

Every carrier on ORD to FNT combined arrived on time 65.0% of the time across 1,975 flights, so OO 5603 is about level with it. Across its whole network SkyWest Airlines managed 79.0%, which this flight trails by 13 points.

OO 5603 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5603thin sample	300	66.2%	102 min	3.33%	C−
All SkyWest Airlines on ORD–FNT	1,975	65.0%	98 min	4.10%	C−
All carriers on ORD–FNT	1,975	65.0%	98 min	4.10%	C−
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 5603 quarter by quarter

Quarter by quarter OO 5603 held fairly steady: 69.7% in Jul–Sep 2025, 69.0% in Oct–Dec 2025 and 59.8% in Jan–Mar 2026. A spread of 10 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202591 flights69.7%
Oct–Dec 202589 flights69.0%
Jan–Mar 202690 flights59.8%
Apr–Jun 202630 flights—

Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5603 did best on Tuesday at 76.7% on time and worst on Saturday at 54.8%. Each day rests on about 43 flights, so a gap of 22 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 5603 runs late

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 9,989 reported delay minutes.

Carrier
28%
Late-arriving aircraft
26%
National Airspace System
25%
Extreme weather
21%

Extreme weather accounts for 21% 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 quarterly figures above are the more useful view of the risk. The national share is 6%, so this operation carries roughly 3.4 times the usual weather exposure. The split is drawn from 9,989 delay minutes reported on OO 5603.

Cancellations run at 3.33%, against 1.81% nationally. That is about one flight in 30 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 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. 18.3% 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.

The same number turns up on two other city pairs in the data, including ORD to BWI (15) and SCE to ORD (7), but none flew often enough under OO 5603 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ORD to FNT only.

One caution: this is a thin sample. 300 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 5603

For a booking, the cancellation rate is the figure to plan around on OO 5603: 3.33% of its 300 scheduled flights did not operate. A late arrival costs close to two hours, but a cancellation costs the day, so leave a later option open.

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