Flight number record
DL 1088
Delta Air Lines · Salt Lake City to San Francisco
- Route
- SLC → SFO
- Departs
- 15:00
- Flights
- 364
- Period
- July 2025 to June 2026
Historical statistics for July 2025 to June 2026, not live status. For today’s DL 1088, check with Delta Air Lines.
DL 1088 draws a C. About one flight in three arrives at least 15 minutes late, and the typical late arrival is about an hour behind schedule. Build slack into anything you connect to. That rests on 364 flights, with a median arrival 2 minutes early.
The national on-time rate over the same period is 77.6%, so DL 1088 runs 10 points behind the country as a whole. Across a thousand flights that is about 97 extra late arrivals.
Key figures
On time
67.9%
Arrivals under 15 minutes late, of 358 completed flights
Avg delay
61 min
Across delayed arrivals only, not all flights
Cancelled
1.10%
National rate is 1.81%
1 hour+ late
10.9%
National rate is 8.1%
These figures cover 364 flights between July 2025 and June 2026. Beyond the headline rate, 10.9% 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 1088 flies
DL 1088 flies SLC to SFO without a single fixed slot. Its most common scheduled departure was 15:00, used on 175 of 364 flights, with 15:01 (51 flights) and 15:07 (38 flights) next. Carriers retime flights through the season, so the rates here blend slightly different positions in the aircraft's day.
- Departs 15:00175 flights48.1%
- Departs 15:0151 flights14.0%
- Departs 15:0738 flights10.4%
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 15:00 departure sits in the 2pm–5pm window. Across every US flight scheduled in that window the on-time rate is 72.4%, and DL 1088 runs 5 points worse at 67.9%. Midday slots inherit some of the morning's delays without yet carrying the full weight of the evening's.
Against the route
DL 1088 next to SLC to SFO
Every carrier on SLC to SFO combined arrived on time 69.0% of the time across 3,472 flights, so DL 1088 is about level with it. Delta flew 1,706 flights on the same city pair under all its flight numbers, including this one, and those ran 67.4% on time. Across its whole network Delta Air Lines managed 81.6%, which this flight trails by 14 points.
| Compared with | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| DL 1088thin sample | 364 | 67.9% | 61 min | 1.10% | C |
| All Delta Air Lines on SLC–SFO | 1,706 | 67.4% | 52 min | 0.88% | C+ |
| All carriers on SLC–SFO | 3,472 | 69.0% | 64 min | 0.95% | C+ |
| Delta Air Lines, whole network | 1,038,570 | 81.6% | 71 min | 1.62% | B |
Across the year
DL 1088 quarter by quarter
DL 1088 did not run the same all year. Its best quarter was Jul–Sep 2025 at 82.2% on time and its weakest Apr–Jun 2026 at 45.6%, a swing of 37 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 flights82.2%
- Oct–Dec 202591 flights71.1%
- Jan–Mar 202690 flights72.7%
- Apr–Jun 202691 flights45.6%
Scale runs 35% to 90%. Rows with fewer than 30 flights show a dash.
By weekday, DL 1088 did best on Tuesday at 76.5% on time and worst on Wednesday at 62.7%. Each day rests on about 52 flights, so a gap of 14 points is worth noticing but could still narrow in another year.
Delay causes
Why DL 1088 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 7,059 reported delay minutes.
- 41%National Airspace System
- 33%Carrier
- 25%Late-arriving aircraft
- 1%Extreme weather
41% of delay minutes are charged to the National Airspace System: air traffic volume, runway configuration, ground stops. No carrier can price its way out of that, which is why airport choice moves the number here more than carrier choice does. That is 2,916 minutes out of 7,059, against a national NAS share of 21%. The split is drawn from 7,059 delay minutes reported on DL 1088.
Cancellations sit at 1.10% against a national 1.81%, which is ordinary. Diversions add another 0.55%.
Connections and routes
What a delay on this flight costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 10.9% of arrivals land a full hour or more behind schedule, against 8.1% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.
The 599 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. It is also long enough that the aircraft usually flies three or four legs a day rather than six, which slows how fast delay compounds.
DL 1088 is not only a SLC to SFO flight. It also flew SFO to SLC (358 flights, 72.0% 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. 364 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 |
|---|---|---|---|---|---|
| SFO to SLCthin sample | 358 | 72.0% | 99 min | 1.12% | C |
What to do with this
Booking DL 1088
For a booking, read DL 1088 as 67.9% on time with 1.10% cancelled over 364 flights. Those are rates from the past twelve months, not a forecast for any particular day.
Related
Where to go next
- SLC to SFO, every carrier and departure
- SFO to SLC, the return direction
- Delta Air Lines 902 on the same route65.8%
- Delta Air Lines 920 on the same route67.7%
- Delta Air Lines 1091 on the same route69.8%
- Delta Air Lines 2762 on the same route64.7%
- Salt Lake City International (SLC) delay statistics
- San Francisco International (SFO) 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
- How often a connection fails at the major US hubs
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.