Flight number record

OO 5437

SkyWest Airlines · Chicago to Duluth

Route: ORD → DLH
Departs: 12:45
Flights: 298
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 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 298 flights, with a median arrival 1 minute late.

The national on-time rate over the same period is 77.6%, so OO 5437 runs 13 points behind the country as a whole. Across a thousand flights that is about 128 extra late arrivals.

On time

64.8%

Arrivals under 15 minutes late, of 290 completed flights

Avg delay

77 min

Across delayed arrivals only, not all flights

Cancelled

2.35%

National rate is 1.81%

1 hour+ late

14.1%

National rate is 8.1%

These figures cover 298 flights between July 2025 and June 2026. Beyond the headline rate, 14.1% 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 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 298 flights, with 12:50 (70 flights) and 12:48 (37 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 12:45127 flights42.6%
Departs 12:5070 flights23.5%
Departs 12:4837 flights12.4%

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 12:45 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and OO 5437 runs 14 points worse at 64.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

OO 5437 next to ORD to DLH

Every carrier on ORD to DLH combined arrived on time 64.6% of the time across 1,216 flights, so OO 5437 is about level with it. SkyWest flew 1,133 flights on the same city pair under all its flight numbers, including this one, and those ran 63.7% on time. Across its whole network SkyWest Airlines managed 79.0%, which this flight trails by 14 points.

OO 5437 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 5437thin sample	298	64.8%	77 min	2.35%	D
All SkyWest Airlines on ORD–DLH	1,133	63.7%	79 min	3.62%	D−
All carriers on ORD–DLH	1,216	64.6%	80 min	3.87%	D−
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	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 74.4% on time and its weakest Jan–Mar 2026 at 56.0%, a swing of 18 points on roughly 99 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 202592 flights74.4%
Oct–Dec 202592 flights59.6%
Jan–Mar 202687 flights56.0%
Apr–Jun 202627 flights—

Scale runs 50% to 80%. Rows with fewer than 30 flights show a dash.

By weekday, OO 5437 did best on Thursday at 72.1% on time and worst on Wednesday at 56.1%. Each day rests on about 43 flights, so a gap of 16 points is worth noticing but could still narrow in another year.

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 7,829 reported delay minutes.

Late-arriving aircraft
33%
Carrier
29%
National Airspace System
26%
Extreme weather
11%

No single cause dominates. late-arriving aircraft at 33%, carrier at 29% and national airspace system at 26% split the 7,829 reported delay minutes between them. An even spread like this usually means the operation is running close to its designed capacity with no one obvious weak point, and it is the hardest pattern for a traveller to route around. The split is drawn from 7,829 delay minutes reported on OO 5437.

Cancellations sit at 2.35% against a national 1.81%, which is ordinary. Diversions add another 0.34%.

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. 14.1% 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 three 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. 298 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, OO 5437 is a flight to put a long connection behind. 14.1% 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