Carrier route record
DLATL→SAN
Delta Air Lines · Atlanta to San Diego
- Flights
- 2,172
- Period
- July 2025 to June 2026
- Share of route
- 90%
- Carriers
- 2
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Delta Air Lines.
Delta on ATL to SAN lands a B+, about a point better than the national rate of 77.6%. About 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 2,172 flights, with a median arrival 2 minutes early.
The US average over the same twelve months is 77.6%, so there is little to separate Delta on ATL to SAN from the country as a whole. The variation that matters here is internal: which carrier, and what time of day.
Key figures
On time
78.4%
Arrivals under 15 minutes late, of 2,142 completed flights
Avg delay
48 min
Across delayed arrivals only, not all flights
Cancelled
0.69%
National rate is 1.81%
Whole route
78.8%
Every carrier on ATL to SAN, 2,413 flights
These figures cover 2,172 flights between July 2025 and June 2026. The median arrival is 2 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.
Carrier by carrier
Delta against every carrier on ATL to SAN
Delta flew 2,172 of the 2,413 flights on ATL to SAN, most of the route. Its 78.4% on time is about level with the route as a whole at 78.8%. Ranked by on-time rate it is last of two carriers on the route, where the range runs from Alaska at 82.0% to Delta at 78.4%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
Only one carrier clears this site's 365-flight floor here, so there is no comparison to draw. The table below is the full picture.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| Alaska Airlinesthin sample | 241 | 82.0% | 38 min | 0.00% | B+ |
| Delta Air Lines (this page) | 2,172 | 78.4% | 48 min | 0.69% | B+ |
Flight by flight
Delta flight numbers on ATL to SAN
Departure window
When Delta runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 14 points, against half a point between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am—
- 8am–11am437 flights87.3%
- 11am–2pm404 flights79.9%
- 2pm–5pm412 flights77.7%
- 5pm–8pm554 flights73.9%
- 8pm–5am365 flights73.8%
Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.
Book the morning departure. Flights leaving between 8am–11am arrive on time 87.3% of the time, against 73.8% for the overnight window. That is 14 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 5pm–8pm window is the busiest, with 554 flights scheduled in it.
Across the year
Delta on ATL to SAN through the year
July is the worst month at 71.1% on time, 15 points below March, the best at 86.1%. Summer afternoon convection and peak-season schedules land on the same weeks every year, so this is a pattern you can book around rather than a run of bad luck. October was the busiest month here, with 202 flights.
Across the week, Wednesday is the strongest day at 85.2% on time and Thursday the weakest at 72.5%. 13 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Delta runs late on this route
One category carries most of the weight here. Carrier accounts for 46% of the 22,000 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.
- 46%Carrier
- 29%National Airspace System
- 20%Late-arriving aircraft
- 5%Extreme weather
The largest share of delay minutes, 46%, 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 10,000 of the 22,000 delay minutes reported here. The split is drawn from 22,070 reported delay minutes.
Cancellations are rare at 0.69%, 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 stage length
What a delay here costs
Badly late arrivals are rare here: only 4.9% land an hour or more behind schedule, against 8.1% 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.
At 1,892 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 return leg is a different operation and performs like one: it runs 86.9% on time across 2,171 flights, 9 points above this direction. Departure banks, aircraft rotations and the congestion at each end all differ, so scoring the two directions together would average away a real 9 points of difference.
The sample behind these figures is 2,172 flights, enough that the headline rate is stable to within roughly a point. The hour-block and month splits divide that further, so read the thinner bars with more caution than the headline.
What to do with this
Booking Delta on ATL to SAN
Put together: the calendar is the biggest lever here, not the carrier or the hour. March runs 86.1% on time and July 71.1%, a swing of 15 points. If the dates move at all, move them out of July before you think about anything else. 2,142 completed flights over 12 months sit behind that.
Related
Where to go next
- ATL to SAN, every carrier
- Delta on SAN to ATL, the return leg
- Alaska Airlines on ATL to SAN82.0%
- Delta Air Lines network-wide record
- Hartsfield-Jackson Atlanta International (ATL) delay statistics
- San Diego International (SAN) delay statistics
- The best time of day to fly, according to 7.04 million flight records
- Worst months to fly in the US, ranked by the data
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.