Flight number record

OO 3684

SkyWest Airlines · Detroit to Lansing

Route: DTW → LAN
Departs: 22:55
Flights: 294
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s OO 3684, 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 3684 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 close to two hours on average. That is a workable record, not a spotless one. That rests on 294 flights, with a median arrival 6 minutes early.

On time

78.4%

Arrivals under 15 minutes late, of 291 completed flights

Avg delay

109 min

Across delayed arrivals only, not all flights

Cancelled

1.02%

National rate is 1.81%

1 hour+ late

11.0%

National rate is 8.1%

These figures cover 294 flights between July 2025 and June 2026. Beyond the headline rate, 11.0% 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 3684 flies

OO 3684 flies DTW to LAN without a single fixed slot. Its most common scheduled departure was 22:55, used on 91 of 294 flights, with 22:50 (56 flights) and 21:35 (35 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 22:5591 flights31.0%
Departs 22:5056 flights19.0%
Departs 21:3535 flights11.9%

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 22:55 departure sits in the 8pm–5am window. Across every US flight scheduled in that window the on-time rate is 70.5%, and OO 3684 runs 8 points better at 78.4%. 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 3684 next to DTW to LAN

Every carrier on DTW to LAN combined arrived on time 75.1% of the time across 881 flights, so OO 3684 is 3 points ahead of it. Across its whole network SkyWest Airlines managed 79.0%, close to this flight's figure.

OO 3684 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
OO 3684thin sample	294	78.4%	109 min	1.02%	B
All SkyWest Airlines on DTW–LAN	881	75.1%	101 min	0.91%	B+
All carriers on DTW–LAN	881	75.1%	101 min	0.91%	B+
SkyWest Airlines, whole network	852,935	79.0%	88 min	1.77%	B

Across the year

OO 3684 quarter by quarter

OO 3684 did not run the same all year. Its best quarter was Jul–Sep 2025 at 90.2% on time and its weakest Jan–Mar 2026 at 61.4%, a swing of 29 points on roughly 74 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 flights90.2%
Oct–Dec 202557 flights78.9%
Jan–Mar 202686 flights61.4%
Apr–Jun 202659 flights83.1%

Scale runs 55% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, OO 3684 did best on Saturday at 89.7% on time and worst on Sunday at 63.4%. Each day rests on about 42 flights, so a gap of 26 points is worth noticing but could still narrow in another year.

Delay causes

Why OO 3684 runs late

One category carries most of the weight here. Carrier accounts for 84% of the 6,868 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
84%
Extreme weather
8%
National Airspace System
7%

The largest share of delay minutes, 84%, 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 5,802 of the 6,868 delay minutes reported here. The split is drawn from 6,868 delay minutes reported on OO 3684.

Cancellations sit at 1.02% 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. 11.0% 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 four other city pairs in the data, including DTW to GRB (16), SLC to BOI (5) and BOI to SLC (5), but none flew often enough under OO 3684 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to LAN only.

One caution: this is a thin sample. 294 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 3684

For a booking, read OO 3684 as 78.4% on time with 1.02% cancelled over 294 flights. Those are rates from the past twelve months, not a forecast for any particular day.

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