Flight number record
OO 5437
SkyWest Airlines · Chicago to Duluth
- Route
- ORD → DLH
- Departs
- 12:45
- Flights
- 277
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s OO 5437, 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 5437 draws a D. About one flight in three arrives at least 15 minutes late, and the typical late arrival is a little over an hour behind schedule. Build slack into anything you connect to. That rests on 277 flights, with a median arrival 2 minutes late.
The national on-time rate over the same period is 77.3%, so OO 5437 runs 13 points behind the country as a whole. Across a thousand flights that is about 134 extra late arrivals.
Key figures
On time
63.9%
Arrivals under 15 minutes late, of 269 completed flights
Avg delay
76 min
Across delayed arrivals only, not all flights
Cancelled
2.53%
National rate is 1.89%
1 hour+ late
15.2%
National rate is 8.3%
These figures cover 277 flights between September 2025 and August 2026. Beyond the headline rate, 15.2% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When OO 5437 flies
OO 5437 flies ORD to DLH without a single fixed slot. Its most common scheduled departure was 12:45, used on 127 of 277 flights, with 12:40 (68 flights) and 12:54 (37 flights) next.
- Departs 12:45127 flights45.8%
- Departs 12:4068 flights24.5%
- Departs 12:5437 flights13.4%
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 12:45 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and OO 5437 runs 14 points worse at 63.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
OO 5437 next to ORD to DLH
Every carrier on ORD to DLH combined arrived on time 65.3% of the time across 1,238 flights, so OO 5437 is about level with it. SkyWest flew 1,114 flights on the same city pair under all its flight numbers, including this one, and those ran 64.0% on time. Across its whole network SkyWest Airlines managed 78.7%, which this flight trails by 15 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| OO 5437thin sample | 277 | 63.9% | 76 min | 2.53% | D |
| All SkyWest Airlines on ORD–DLH | 1,114 | 64.0% | 79 min | 4.49% | D− |
| All carriers on ORD–DLH | 1,238 | 65.3% | 80 min | 4.52% | C− |
| SkyWest Airlines, whole network | 855,406 | 78.7% | 88 min | 1.79% | B |
Across the year
OO 5437 quarter by quarter
OO 5437 did not run the same all year. Its best quarter was Jul–Sep 2025 at 80.0% on time and its weakest Jan–Mar 2026 at 56.0%, a swing of 24 points on roughly 69 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 flights80.0%
- Oct–Dec 202592 flights59.6%
- Jan–Mar 202687 flights56.0%
- Apr–Jun 202627 flights—
- Jul–Sep 202641 flights69.2%
Scale runs 50% to 85%. Rows with fewer than 30 flights show a dash.
By weekday, OO 5437 did best on Saturday at 71.8% on time and worst on Monday at 57.5%. Each day rests on about 40 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late OO 5437 runs when it is late
The 97 late arrivals split 31 under half an hour, 25 between 30 and 60 minutes, and 41 an hour or more.
- 15+ min early52 flights19.3%
- Within 15 min120 flights44.6%
- 15–29 min late31 flights11.5%
- 30–59 min late25 flights9.3%
- 1–2 hours late20 flights7.4%
- 2+ hours late21 flights7.8%
Scale runs 0% to 100%.
Share of 269 completed flights by arrival against schedule.
Time lost at the gate mostly stays lost. Of 76 departures that left 15 minutes late or more, only 7 made it up before arrival. In the other direction, 28 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 DLH.
The worst days
Worst days for OO 5437
The latest arrival of the period was on 10 March 2026, 5 hours 11 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The same cause led on three of the five worst days.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 10 March 2026 | 5 hours 11 minutes | Carrier |
| 3 December 2025 | 4 hours 54 minutes | Late-arriving aircraft |
| 10 November 2025 | 3 hours 49 minutes | Carrier |
| 24 July 2026 | 3 hours 44 minutes | Carrier |
| 6 March 2026 | 3 hours 35 minutes | Late-arriving aircraft |
Delay causes
Why OO 5437 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 7,324 reported delay minutes.
- 36%Carrier
- 33%Late-arriving aircraft
- 20%National Airspace System
- 12%Extreme weather
Extreme weather accounts for 12% 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 1.9 times the usual weather exposure. The split is drawn from 7,324 delay minutes reported on OO 5437.
Cancellations run at 2.53%, against 1.89% nationally. That is about one flight in 40 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
15.2% 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 four other city pairs in the data, including TUS to ORD (32), DLH to ORD (11) and SFO to SEA (6), but none flew often enough under OO 5437 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to ORD to DLH only.
One caution: this is a thin sample. 277 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 5437
For a booking, the cancellation rate is the figure to plan around on OO 5437: 2.53% of its 277 scheduled flights did not operate. A late arrival costs a little over an hour, but a cancellation costs the day, so leave a later option open.
Related
Where to go next
- ORD to DLH, every carrier and departure
- DLH to ORD, the return direction
- SkyWest Airlines 5819 on the same route71.5%
- 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
- Why the first flight of the morning is statistically safest
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.