Flight number record
OO 5603
SkyWest Airlines · Chicago to Flint
- Route
- ORD → FNT
- Departs
- 20:03
- Flights
- 260
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 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 D−. 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 260 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.3%, so OO 5603 runs 12 points behind the country as a whole. Across a thousand flights that is about 124 extra late arrivals.
Key figures
On time
64.9%
Arrivals under 15 minutes late, of 251 completed flights
Avg delay
101 min
Across delayed arrivals only, not all flights
Cancelled
3.46%
National rate is 1.89%
1 hour+ late
18.3%
National rate is 8.3%
These figures cover 260 flights between September 2025 and August 2026. Beyond the headline rate, 18.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 5603 flies
OO 5603 flies ORD to FNT without a single fixed slot. Its most common scheduled departure was 20:03, used on 72 of 260 flights, with 20:08 (48 flights) and 20:10 (46 flights) next.
- Departs 20:0372 flights27.7%
- Departs 20:0848 flights18.5%
- Departs 20:1046 flights17.7%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 20:03 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.1%, and OO 5603 runs 5 points worse at 64.9%. By that time of day most aircraft have flown several legs already, and whatever went wrong earlier is still in the schedule.
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Against the route
OO 5603 next to ORD to FNT
Every carrier on ORD to FNT combined arrived on time 64.5% of the time across 1,866 flights, so OO 5603 is about level with it. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 14 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 5603thin sample | 260 | 64.9% | 101 min | 3.46% | D− |
| All SkyWest Airlines on ORD–FNT | 1,866 | 64.5% | 100 min | 4.18% | D− |
| All carriers on ORD–FNT | 1,866 | 64.5% | 100 min | 4.18% | D− |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 5603 quarter by quarter
OO 5603 did not run the same all year. Its best quarter was Jul–Sep 2025 at 76.7% on time and its weakest Jan–Mar 2026 at 59.8%, a swing of 17 points on roughly 87 flights a quarter. The twelve-month rate averages over that, so if you are flying in a weak quarter the quarter's own figure is the better guide.
- Jul–Sep 202530 flights76.7%
- Oct–Dec 202589 flights69.0%
- Jan–Mar 202690 flights59.8%
- Apr–Jun 202630 flights—
- Jul–Sep 202621 flights—
Scale runs 50% to 80%. Rows with fewer than 30 flights show a dash.
By weekday, OO 5603 did best on Tuesday at 73.0% on time and worst on Saturday at 52.8%. Each day rests on about 37 flights, so a gap of 20 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 5603 runs when it is late
When OO 5603 is late it tends to be very late: 46 of its 88 late arrivals were an hour or more behind, and 21 were two hours or more.
- 15+ min early49 flights19.5%
- Within 15 min114 flights45.4%
- 15–29 min late21 flights8.4%
- 30–59 min late21 flights8.4%
- 1–2 hours late25 flights10.0%
- 2+ hours late21 flights8.4%
Scale runs 0% to 100%.
Share of 251 completed flights by arrival against schedule.
11 of 85 late departures made up the time and arrived on time, 13% of them. In the other direction, 14 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at FNT.
The worst days
Worst days for OO 5603
The latest arrival of the period was on 30 January 2026, 15 hours 11 minutes behind schedule; most of its delay minutes were filed as extreme weather. The five worst days are spread across January, April, September and November, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 30 January 2026 | 15 hours 11 minutes | Extreme weather |
| 16 April 2026 | 13 hours 25 minutes | Extreme weather |
| 3 September 2025 | 10 hours 44 minutes | Carrier |
| 15 April 2026 | 3 hours 45 minutes | Late-arriving aircraft |
| 26 November 2025 | 3 hours 40 minutes | National Airspace System |
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 8,859 reported delay minutes.
- 31%Carrier
- 27%Late-arriving aircraft
- 21%Extreme weather
- 21%National Airspace System
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 3.5 times the usual weather exposure. The split is drawn from 8,859 delay minutes reported on OO 5603.
Cancellations run at 3.46%, against 1.89% 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
18.3% of arrivals land a full hour or more behind schedule, against 8.3% nationally. Ninety minutes is the honest minimum for a connection here, and two hours if the onward flight is on a separate ticket.
The same number turns up on three other city pairs in the data, including SDF to ORD (41), 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. 260 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: 3.46% of its 260 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.
Related
Where to go next
- ORD to FNT, every carrier and departure
- FNT to ORD, the return direction
- Chicago O'Hare International (ORD) delay statistics
- SkyWest Airlines on-time record
- Every SkyWest Airlines flight number with a record
- The most and least reliable flight numbers in the US
- What a cancellation rate actually tells you (and what it hides)
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.