Flight number record
DL 1659
Delta Air Lines · Salt Lake City to Las Vegas
- Route
- SLC → LAS
- Departs
- 11:35
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 1659, check with Delta Air Lines.
DL 1659 sits in the middle of the pack with a C+. Close to three flights in four arrive on time by the DOT's definition, 2 points worse than the national rate of 77.3%. The late ones land about an hour behind schedule. That rests on 365 flights, with a median arrival 2 minutes early.
Key figures
On time
74.9%
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 1.89%
1 hour+ late
8.0%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. Beyond the headline rate, 8.0% of arrivals land a full hour or more behind schedule, against 8.3% nationally.
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Schedule
When DL 1659 flies
DL 1659 flies SLC to LAS without a single fixed slot. Its most common scheduled departure was 11:35, used on 130 of 365 flights, with 11:40 (107 flights) and 11:45 (65 flights) next.
- Departs 11:35130 flights35.6%
- Departs 11:40107 flights29.3%
- Departs 11:4565 flights17.8%
Scale runs 0% to 100%.
Share of scheduled departures at each local time. Times used on fewer than one flight in ten are not listed.
A 11:35 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and DL 1659 runs 3 points worse at 74.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
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Against the route
DL 1659 next to SLC to LAS
Every carrier on SLC to LAS combined arrived on time 77.5% of the time across 3,724 flights, so DL 1659 is 3 points behind it. Delta flew 1,716 flights on the same city pair under all its flight numbers, including this one, and those ran 79.0% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight trails by 6 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1659 | 365 | 74.9% | 61 min | 0.55% | C+ |
| All Delta Air Lines on SLC–LAS | 1,716 | 79.0% | 56 min | 0.64% | B+ |
| All carriers on SLC–LAS | 3,724 | 77.5% | 62 min | 0.67% | B+ |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | 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 86.7% on time and its weakest Oct–Dec 2025 at 67.0%, a swing of 20 points on roughly 73 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 202530 flights86.7%
- Oct–Dec 202592 flights67.0%
- Jan–Mar 202690 flights76.4%
- Apr–Jun 202691 flights74.7%
- Jul–Sep 202662 flights79.0%
Scale runs 60% to 90%.
By weekday, DL 1659 did best on Wednesday at 82.7% on time and worst on Friday at 64.7%. Each day rests on about 52 flights, so a gap of 18 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 1659 runs when it is late
The 91 late arrivals split 37 under half an hour, 25 between 30 and 60 minutes, and 29 an hour or more.
- 15+ min early50 flights13.8%
- Within 15 min222 flights61.2%
- 15–29 min late37 flights10.2%
- 30–59 min late25 flights6.9%
- 1–2 hours late19 flights5.2%
- 2+ hours late10 flights2.8%
Scale runs 0% to 100%.
Share of 363 completed flights by arrival against schedule.
8 of 60 late departures made up the time and arrived on time, 13% of them. In the other direction, 39 flights left on time yet arrived 15 minutes late or more, so that delay built up after pushback: in the air, in a holding pattern or on the ground at LAS.
The worst days
Worst days for DL 1659
The latest arrival of the period was on 27 June 2026, 5 hours 1 minute behind schedule; most of its delay minutes were filed as extreme weather. On three of the five worst days the largest share was filed as carrier-caused (crew, maintenance, fuelling, baggage).
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 27 June 2026 | 5 hours 1 minute | Extreme weather |
| 18 February 2026 | 4 hours 18 minutes | Extreme weather |
| 13 October 2025 | 3 hours 46 minutes | Carrier |
| 9 October 2025 | 3 hours 42 minutes | Carrier |
| 30 August 2026 | 3 hours 37 minutes | Carrier |
Delay causes
Why DL 1659 runs late
Carrier accounts for 46% of the 5,560 delay minutes carriers reported here, and the remaining four split what is left.
- 46%Carrier
- 28%National Airspace System
- 16%Late-arriving aircraft
- 10%Extreme weather
The largest share of delay minutes, 46%, falls under carrier control: crew scheduling, maintenance, fuelling, baggage. It accounts for 2,570 of the 5,560 delay minutes reported here. The split is drawn from 5,560 delay minutes reported on DL 1659.
Cancellations are rare at 0.55%, below the national 1.89% 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
8.0% of arrivals land an hour or more late, close to the national 8.3%, so 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, 81.2% 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.
| Also flown as | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| LAS to SLCthin sample | 327 | 81.2% | 74 min | 0.61% | B+ |
What to do with this
Booking DL 1659
For a booking, read DL 1659 as 74.9% on time with 0.55% cancelled over 365 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SLC to LAS, every carrier and departure
- LAS to SLC, the return direction
- Delta Air Lines 1672 on the same route72.9%
- Delta Air Lines 1662 on the same route79.6%
- Delta Air Lines 1698 on the same route93.3%
- Frontier Airlines 2575 on the same route79.3%
- Salt Lake City International (SLC) delay statistics
- Harry Reid International (LAS) delay statistics
- Delta Air Lines on-time record
- Every Delta Air Lines flight number with a record
- The most and least reliable flight numbers in the US
- Connecting flights: how much buffer the data says you need
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, September 2025 to August 2026. Last updated ; recomputed monthly. How this data is collected.