Flight number record
DL 829
Delta Air Lines · Salt Lake City to Los Angeles
- Route
- SLC → LAX
- Departs
- 11:30
- Flights
- 365
- Period
- September 2025 to August 2026
Historical statistics for September 2025 to August 2026, not live status. For today’s DL 829, check with Delta Air Lines.
DL 829 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 77.3%. When something does go wrong the average delay runs roughly 55 minutes. That rests on 365 flights, with a median arrival 6 minutes early.
Set against the rest of the country, DL 829's record is 9 points better than the US average of 77.3%. That gap is worth roughly 92 fewer late arrivals for every thousand flights.
Key figures
On time
86.5%
Arrivals under 15 minutes late, of 362 completed flights
Avg delay
53 min
Across delayed arrivals only, not all flights
Cancelled
0.82%
National rate is 1.89%
1 hour+ late
3.0%
National rate is 8.3%
These figures cover 365 flights between September 2025 and August 2026. The median arrival is 6 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.
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Schedule
When DL 829 flies
DL 829 flies SLC to LAX without a single fixed slot. Its most common scheduled departure was 11:30, used on 88 of 365 flights, with 11:20 (85 flights) and 11:15 (61 flights) next.
- Departs 11:3088 flights24.1%
- Departs 11:2085 flights23.3%
- Departs 11:1561 flights16.7%
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 11:30 departure sits in the 11am–2pm window. Across every US flight scheduled in that window the on-time rate is 78.3%, and DL 829 runs 8 points better at 86.5%. 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 829 next to SLC to LAX
Every carrier on SLC to LAX combined arrived on time 85.6% of the time across 4,196 flights, so DL 829 is about level with it. Delta flew 2,459 flights on the same city pair under all its flight numbers, including this one, and those ran 83.5% on time. Across its whole network Delta Air Lines managed 81.1%, which this flight beats by 5 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 829 | 365 | 86.5% | 53 min | 0.82% | A+ |
| All Delta Air Lines on SLC–LAX | 2,459 | 83.5% | 52 min | 0.53% | B+ |
| All carriers on SLC–LAX | 4,196 | 85.6% | 55 min | 0.48% | A+ |
| Delta Air Lines, whole network | 1,039,517 | 81.1% | 71 min | 1.74% | B |
Across the year
DL 829 quarter by quarter
DL 829 did not run the same all year. Its best quarter was Oct–Dec 2025 at 93.4% on time and its weakest Jan–Mar 2026 at 75.3%, a swing of 18 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 flights93.3%
- Oct–Dec 202592 flights93.4%
- Jan–Mar 202690 flights75.3%
- Apr–Jun 202691 flights90.1%
- Jul–Sep 202662 flights83.6%
Scale runs 65% to 100%.
By weekday, DL 829 did best on Wednesday at 94.2% on time and worst on Saturday at 76.9%. Each day rests on about 52 flights, so a gap of 17 points is worth noticing but could still narrow in another year.
Arrival by arrival
How late DL 829 runs when it is late
Most of the lateness is short. 26 of the 49 late arrivals were under half an hour behind, and 11 reached an hour or more.
- 15+ min early89 flights24.6%
- Within 15 min224 flights61.9%
- 15–29 min late26 flights7.2%
- 30–59 min late12 flights3.3%
- 1–2 hours late6 flights1.7%
- 2+ hours late5 flights1.4%
Scale runs 0% to 100%.
Share of 362 completed flights by arrival against schedule.
12 of 52 late departures made up the time and arrived on time, 23% of them. 9 flights left on time and still arrived late.
The worst days
Worst days for DL 829
The latest arrival of the period was on 18 April 2026, 4 hours 37 minutes behind schedule; most of its delay minutes were filed as carrier-caused (crew, maintenance, fuelling, baggage). The five worst days are spread across April, February, June, January and July, with no single month standing out.
| Date | Arrived late by | Largest filed cause |
|---|---|---|
| 18 April 2026 | 4 hours 37 minutes | Carrier |
| 18 February 2026 | 4 hours 8 minutes | Extreme weather |
| 27 June 2026 | 3 hours 27 minutes | Extreme weather |
| 18 January 2026 | 2 hours 30 minutes | Late-arriving aircraft |
| 24 July 2026 | 2 hours 12 minutes | Late-arriving aircraft |
Delay causes
Why DL 829 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 2,579 reported delay minutes.
- 38%Late-arriving aircraft
- 35%Carrier
- 18%Extreme weather
- 10%National Airspace System
Extreme weather accounts for 18% 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 3.0 times the usual weather exposure. The split is drawn from 2,579 delay minutes reported on DL 829.
Cancellations are rare at 0.82%, 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
Badly late arrivals are rare here: only 3.0% land an hour or more behind schedule, against 8.3% 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.
The 590 miles between these two airports put this in the middle of the US network, around two and a half to three hours of block time. That is enough cruise to absorb a ten-minute late pushback and not enough to absorb thirty.
Every one of the 365 flights under DL 829 in the data flew SLC to LAX. 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. 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.
What to do with this
Booking DL 829
For a booking, DL 829 has one of the better records a US domestic flight can show: 86.5% on time and 0.82% cancelled. That is a base rate, not a promise about any single day.
Related
Where to go next
- SLC to LAX, every carrier and departure
- LAX to SLC, the return direction
- Delta Air Lines 841 on the same route78.1%
- Delta Air Lines 1087 on the same route91.1%
- Delta Air Lines 1142 on the same route73.7%
- Delta Air Lines 1095 on the same route91.1%
- Delta Air Lines 1161 on the same route81.4%
- Salt Lake City International (SLC) delay statistics
- Los Angeles International (LAX) 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
- Why the first flight of the morning is statistically safest
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.