Flight number record

DL 421

Delta Air Lines · Detroit to Las Vegas

Route: DTW → LAS
Departs: 12:32
Flights: 361
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 421, check with Delta Air Lines.

DL 421 lands a B+, level with the national rate of 77.6%. Roughly one flight in five arrives 15 minutes late or worse, and those flights are late by roughly 50 minutes on average. That is a workable record, not a spotless one. That rests on 361 flights, with a median arrival 1 minute early.

On time

77.8%

Arrivals under 15 minutes late, of 361 completed flights

Avg delay

52 min

Across delayed arrivals only, not all flights

Cancelled

0.00%

National rate is 1.81%

1 hour+ late

6.4%

National rate is 8.1%

These figures cover 361 flights between July 2025 and June 2026. On-time means an arrival less than 15 minutes after the scheduled gate time, the same threshold the Department of Transportation uses in its own reports. Cancelled and diverted flights are excluded from the on-time rate and counted separately, which is why the cancellation column matters on its own.

Schedule

When DL 421 flies

DL 421 flies DTW to LAS without a single fixed slot. Its most common scheduled departure was 12:32, used on 85 of 361 flights, with 12:15 (85 flights) and 12:20 (47 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 12:3285 flights23.5%
Departs 12:1585 flights23.5%
Departs 12:2047 flights13.0%

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 12:32 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 421 runs level with that at 77.8%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 421 next to DTW to LAS

Every carrier on DTW to LAS combined arrived on time 76.1% of the time across 2,843 flights, so DL 421 is 2 points ahead of it. Delta flew 1,897 flights on the same city pair under all its flight numbers, including this one, and those ran 75.9% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 4 points.

DL 421 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 421thin sample	361	77.8%	52 min	0.00%	B+
All Delta Air Lines on DTW–LAS	1,897	75.9%	60 min	0.53%	B+
All carriers on DTW–LAS	2,843	76.1%	56 min	0.49%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 421 quarter by quarter

Quarter by quarter DL 421 held fairly steady: 79.3% in Jul–Sep 2025, 78.7% in Oct–Dec 2025, 74.2% in Jan–Mar 2026 and 79.1% in Apr–Jun 2026. A spread of 5 points is about what a sample of this size moves on its own, so the annual figure is a fair summary.

Jul–Sep 202592 flights79.3%
Oct–Dec 202589 flights78.7%
Jan–Mar 202689 flights74.2%
Apr–Jun 202691 flights79.1%

Scale runs 65% to 85%. Rows with fewer than 30 flights show a dash.

By weekday, DL 421 ranged from 75.0% on Sunday to 82.0% on Thursday. With about 52 flights behind each day, a spread of 7 points is inside normal variation, so the day you fly is not worth changing for this flight.

Delay causes

Why DL 421 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 4,171 reported delay minutes.

Carrier
41%
National Airspace System
23%
Late-arriving aircraft
22%
Extreme weather
13%

Extreme weather accounts for 13% 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 2.1 times the usual weather exposure. The split is drawn from 4,171 delay minutes reported on DL 421.

Cancellations are rare at 0.00%, below the national 1.81% and low enough to earn the plus on the grade. Almost no flights are 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 roughly 50 minutes, which a normal layover absorbs.

At 1,749 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 LAS to DTW (98), but none flew often enough under DL 421 to report a rate for. Carriers move flight numbers between routes, so the figures on this page apply to DTW to LAS only.

One caution: this is a thin sample. 361 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 421

For a booking, read DL 421 as 77.8% on time with 0.00% cancelled over 361 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