Flight number record

DL 1659

Delta Air Lines · Salt Lake City to Las Vegas

Route: SLC → LAS
Departs: 11:30
Flights: 365
Period: July 2025 to June 2026

Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1659, check with Delta Air Lines.

DL 1659 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 365 flights, with a median arrival 3 minutes early.

On time

76.6%

Arrivals under 15 minutes late, of 363 completed flights

Avg delay

61 min

Across delayed arrivals only, not all flights

Cancelled

0.55%

National rate is 1.81%

1 hour+ late

8.3%

National rate is 8.1%

These figures cover 365 flights between July 2025 and June 2026. Beyond the headline rate, 8.3% 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 1659 flies

DL 1659 flies SLC to LAS without a single fixed slot. Its most common scheduled departure was 11:30, used on 100 of 365 flights, with 11:35 (97 flights) and 11:45 (86 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.

Departs 11:30100 flights27.4%
Departs 11:3597 flights26.6%
Departs 11:4586 flights23.6%

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 11:30 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.8%, and DL 1659 runs 2 points worse at 76.6%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.

Against the route

DL 1659 next to SLC to LAS

Every carrier on SLC to LAS combined arrived on time 77.9% of the time across 3,741 flights, so DL 1659 is about level with it. Delta flew 1,714 flights on the same city pair under all its flight numbers, including this one, and those ran 80.2% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 5 points.

DL 1659 against its route and carrier
Compared with	Flights	On time	Avg delay	Cancelled	Grade
DL 1659	365	76.6%	61 min	0.55%	B+
All Delta Air Lines on SLC–LAS	1,714	80.2%	57 min	0.58%	B+
All carriers on SLC–LAS	3,741	77.9%	64 min	0.64%	B+
Delta Air Lines, whole network	1,038,570	81.6%	71 min	1.62%	B

Across the year

DL 1659 quarter by quarter

DL 1659 did not run the same all year. Its best quarter was Jul–Sep 2025 at 88.0% on time and its weakest Oct–Dec 2025 at 67.0%, 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 flights88.0%
Oct–Dec 202592 flights67.0%
Jan–Mar 202690 flights76.4%
Apr–Jun 202691 flights74.7%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

By weekday, DL 1659 did best on Saturday at 88.5% on time and worst on Friday at 68.6%. Each day rests on about 52 flights, so a gap of 20 points is worth noticing but could still narrow in another year.

Delay causes

Why DL 1659 runs late

One category carries most of the weight here. Carrier accounts for 43% of the 5,198 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
43%
National Airspace System
31%
Late-arriving aircraft
16%
Extreme weather
11%

The largest share of delay minutes, 43%, 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 2,228 of the 5,198 delay minutes reported here. The split is drawn from 5,198 delay minutes reported on DL 1659.

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

8.3% 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.

DL 1659 is not only a SLC to LAS flight. It also flew LAS to SLC (327 flights, 83.1% on time) often enough to be scored on its own. Airlines attach one number to several legs of an aircraft's day, and each leg keeps its own record here, so check which city pair is on your booking before reading a rate.

One caution: this is a thin sample. 365 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.

Other routes flown as DL 1659
Also flown as	Flights	On time	Avg delay	Cancelled	Grade
LAS to SLCthin sample	327	83.1%	71 min	0.61%	B+

What to do with this

Booking DL 1659

For a booking, read DL 1659 as 76.6% on time with 0.55% cancelled over 365 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