Flight number record

DL 558

Delta Air Lines · Seattle to Cincinnati

Route: SEA → CVG
Departs: 11:45
Flights: 346
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 558, check with Delta Air Lines.

DL 558 earns an A+. More than four flights in five arrive inside the 15-minute window the DOT uses to define an on-time arrival, which puts it 9 points better than the national rate of 77.6%. When something does go wrong the average delay runs about an hour. That rests on 346 flights, with a median arrival 13 minutes early.

Set against the rest of the country, DL 558's record is 9 points better than the US average of 77.6%. That gap is worth roughly 92 fewer late arrivals for every thousand flights.

On time

86.8%

Arrivals under 15 minutes late, of 341 completed flights

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

0.58%

National rate is 1.81%

1 hour+ late

4.4%

National rate is 8.1%

These figures cover 346 flights between July 2025 and June 2026. The median arrival is 13 minutes early, which is the part an average hides: most flights here are fine, and the on-time rate is decided by a tail of badly late ones. On-time means under 15 minutes late, the DOT's own threshold.

Schedule

When DL 558 flies

DL 558 flies SEA to CVG without a single fixed slot. Its most common scheduled departure was 11:45, used on 172 of 346 flights, with 11:25 (67 flights) and 11:15 (56 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 11:45172 flights49.7%
Departs 11:2567 flights19.4%
Departs 11:1556 flights16.2%

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 11:45 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 558 runs 8 points better at 86.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 558 next to SEA to CVG

Every carrier on SEA to CVG combined arrived on time 81.7% of the time across 793 flights, so DL 558 is 5 points ahead of it. Across its whole network Delta Air Lines managed 81.6%, which this flight beats by 5 points.

DL 558 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 558thin sample	346	86.8%	63 min	0.58%	A+
All Delta Air Lines on SEA–CVGthin sample	362	87.1%	62 min	0.83%	A+
All carriers on SEA–CVG	793	81.7%	51 min	0.88%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 558 quarter by quarter

DL 558 did not run the same all year. Its best quarter was Oct–Dec 2025 at 94.8% on time and its weakest Jan–Mar 2026 at 83.3%, a swing of 12 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 202592 flights83.3%
Oct–Dec 202577 flights94.8%
Jan–Mar 202686 flights83.3%
Apr–Jun 202691 flights86.7%

Scale runs 75% to 100%. Rows with fewer than 30 flights show a dash.

By weekday, DL 558 did best on Friday at 95.7% on time and worst on Sunday at 81.2%. Each day rests on about 49 flights, so a gap of 15 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 558 runs late

One category carries most of the weight here. Carrier accounts for 57% of the 2,811 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
57%
Late-arriving aircraft
25%
National Airspace System
18%

The largest share of delay minutes, 57%, 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 1,608 of the 2,811 delay minutes reported here. The split is drawn from 2,811 delay minutes reported on DL 558.

Cancellations are rare at 0.58%, below the national 1.81% and low enough to earn the plus on the grade. Roughly one flight in 100 is called off; the risk here is arriving late, not not arriving.

Connections and routes

What a delay on this flight costs

Badly late arrivals are rare here: only 4.4% land an hour or more behind schedule, against 8.1% nationally. Connections built on this flight are about as safe as US domestic connections get, though a cancelled flight still ignores every layover you give it.

At 1,965 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.

The same number turns up on one other city pair in the data, including CVG to SEA (16), but none flew often enough under DL 558 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to SEA to CVG only.

One caution: this is a thin sample. 346 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 558

For a booking, DL 558 has one of the better records a US domestic flight can show: 86.8% on time and 0.58% cancelled. That is a base rate, not a promise about any single 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