Flight number record

DL 358

Delta Air Lines · Seattle to Tampa

Route: SEA → TPA
Departs: 11:55
Flights: 363
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 358, check with Delta Air Lines.

DL 358 lands a B+, about a point worse than the national rate of 77.6%. About one flight in four arrives 15 minutes late or worse, and those flights are late by about an hour on average. That is a workable record, not a spotless one. That rests on 363 flights, with a median arrival 2 minutes early.

On time

76.3%

Arrivals under 15 minutes late, of 358 completed flights

Avg delay

55 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

1 hour+ late

6.4%

National rate is 8.1%

These figures cover 363 flights between July 2025 and June 2026. The median arrival is 2 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 358 flies

DL 358 flies SEA to TPA without a single fixed slot. Its most common scheduled departure was 11:55, used on 283 of 363 flights. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 11:55283 flights78.0%

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 11:55 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 358 runs 3 points worse at 76.3%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 358 next to SEA to TPA

Every carrier on SEA to TPA combined arrived on time 78.6% of the time across 976 flights, so DL 358 is 2 points behind it. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 5 points.

DL 358 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 358thin sample	363	76.3%	55 min	0.55%	B+
All Delta Air Lines on SEA–TPAthin sample	363	76.3%	55 min	0.55%	B+
All carriers on SEA–TPA	976	78.6%	48 min	0.61%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 358 quarter by quarter

DL 358 did not run the same all year. Its best quarter was Apr–Jun 2026 at 85.7% on time and its weakest Jul–Sep 2025 at 68.5%, a swing of 17 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 flights68.5%
Oct–Dec 202590 flights75.6%
Jan–Mar 202690 flights75.3%
Apr–Jun 202691 flights85.7%

Scale runs 60% to 90%. Rows with fewer than 30 flights show a dash.

By weekday, DL 358 ranged from 70.6% on Friday to 82.4% on Saturday. With about 52 flights behind each day, a spread of 12 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 358 runs late

One category carries most of the weight here. Carrier accounts for 45% of the 4,673 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
45%
National Airspace System
27%
Late-arriving aircraft
15%
Extreme weather
14%

Extreme weather accounts for 14% 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 2.3 times the usual weather exposure. The split is drawn from 4,673 delay minutes reported on DL 358.

Cancellations are rare at 0.55%, 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

6.4% of arrivals land an hour or more late, close to the national 8.1%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last about an hour, which a normal layover absorbs.

At 2,520 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 358 in the data flew SEA to TPA. 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 358

For a booking, read DL 358 as 76.3% on time with 0.55% 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