Flight number record

DL 2108

Delta Air Lines · Seattle to Chicago

Route: SEA → ORD
Departs: 17:55
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 2108, check with Delta Air Lines.

DL 2108 sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.6%. The late ones land an hour and a half behind schedule. That rests on 363 flights, with a median arrival 5 minutes early.

On time

75.9%

Arrivals under 15 minutes late, of 353 completed flights

Avg delay

94 min

Across delayed arrivals only, not all flights

Cancelled

1.38%

National rate is 1.81%

1 hour+ late

11.9%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. Beyond the headline rate, 11.9% 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 DL 2108 flies

DL 2108 flies SEA to ORD without a single fixed slot. Its most common scheduled departure was 17:55, used on 230 of 363 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 17:55230 flights63.4%

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 17:55 departure sits in the 5pm–8pm window. Across every US flight scheduled in that window the on-time rate is 68.2%, and DL 2108 runs 8 points better at 75.9%. 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

DL 2108 next to SEA to ORD

Every carrier on SEA to ORD combined arrived on time 75.0% of the time across 5,566 flights, so DL 2108 is about level with it. Delta flew 902 flights on the same city pair under all its flight numbers, including this one, and those ran 77.5% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 6 points.

DL 2108 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 2108thin sample	363	75.9%	94 min	1.38%	B
All Delta Air Lines on SEA–ORD	902	77.5%	71 min	1.22%	B
All carriers on SEA–ORD	5,566	75.0%	74 min	1.28%	B
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 2108 quarter by quarter

DL 2108 did not run the same all year. Its best quarter was Jul–Sep 2025 at 83.3% on time and its weakest Oct–Dec 2025 at 62.5%, a swing of 21 points on roughly 91 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 flights83.3%
Oct–Dec 202591 flights62.5%
Jan–Mar 202689 flights75.6%
Apr–Jun 202691 flights82.0%

Scale runs 55% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 2108 did best on Wednesday at 84.6% on time and worst on Monday at 68.0%. Each day rests on about 52 flights, so a gap of 17 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 2108 runs late

One category carries most of the weight here. Carrier accounts for 47% of the 7,965 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
47%
Late-arriving aircraft
28%
National Airspace System
25%

The largest share of delay minutes, 47%, 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 3,748 of the 7,965 delay minutes reported here. The split is drawn from 7,965 delay minutes reported on DL 2108.

Cancellations sit at 1.38% against a national 1.81%, which is ordinary. Diversions add another 1.38%.

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. 11.9% 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.

At 1,721 miles this is transcontinental flying, and long routes get a quiet structural advantage. Scheduled block time on a flight this length carries more padding in absolute minutes, so a twenty-minute late departure often still becomes an on-time arrival. Read the on-time rate here as slightly flattering next to a short-haul route with the same operational quality.

Every one of the 363 flights under DL 2108 in the data flew SEA to ORD. The number was not reused on any other city pair, which makes this a clean record of one route.

One caution: this is a thin sample. 363 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 DL 2108

For a booking, read DL 2108 as 75.9% on time with 1.38% cancelled over 363 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 Delta Air Lines’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