Carrier route record
ASORD→SAN
Alaska Airlines · Chicago to San Diego
- Flights
- 688
- Period
- July 2025 to June 2026
- Share of route
- 18%
- Carriers
- 4
Historical statistics for July 2025 to June 2026, not live status. For today’s flights, check with Alaska Airlines.
Alaska on ORD to SAN sits in the middle of the pack with a C. About seven flights in ten arrive on time by the DOT's definition, 9 points worse than the national rate of 77.6%. The late ones land a little over an hour behind schedule. That rests on 688 flights. The strongest carrier on the route with a full sample, United Airlines, flew 1,672 at 77.0% on time.
The national on-time rate over the same period is 77.6%, so Alaska on ORD to SAN runs 9 points behind the country as a whole. Across a thousand flights that is about 92 extra late arrivals.
Key figures
On time
68.4%
Arrivals under 15 minutes late, of 671 completed flights
Avg delay
70 min
Across delayed arrivals only, not all flights
Cancelled
2.33%
National rate is 1.81%
Whole route
71.2%
Every carrier on ORD to SAN, 3,807 flights
These figures cover 688 flights between July 2025 and June 2026. Beyond the headline rate, 11.3% 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.
Carrier by carrier
Alaska against every carrier on ORD to SAN
Alaska flew 688 of the 3,807 flights on ORD to SAN, about 18% of it. Its 68.4% on time is 3 points worse than the route as a whole, which runs 71.2%. Ranked by on-time rate it is number two of four carriers on the route, where the range runs from United at 77.0% to Frontier at 53.2%. One of those carriers flew fewer than 365 flights here, so treat their positions as rough.
The choice of carrier is not cosmetic here. United Airlines arrives on time 77.0% of the time; American Airlines manages 66.3%. Sample sizes sit next to every figure, because a two-point gap across 1,385 flights means less than a ten-point one.
| Airline | Flights | On time | Avg delay | Cancelled | Grade |
|---|---|---|---|---|---|
| United Airlines | 1,672 | 77.0% | 64 min | 0.30% | B+ |
| Alaska Airlines (this page) | 688 | 68.4% | 70 min | 2.33% | C |
| American Airlines | 1,385 | 66.3% | 65 min | 1.73% | C |
| Frontier Airlinesthin sample | 62 | 53.2% | 103 min | 0.00% | F+ |
United leads American by 11 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.
Departure window
When Alaska runs best on this route
Departure time matters more here than the choice of carrier. The gap between the best and worst window is 12 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.
- 5am–8am28 flights—
- 8am–11am241 flights71.7%
- 11am–2pm—
- 2pm–5pm261 flights70.4%
- 5pm–8pm3 flights—
- 8pm–5am155 flights59.6%
Scale runs 50% to 75%. Rows with fewer than 30 flights show a dash.
The 8pm–5am window is where this operation falls apart: 59.6% on time, against 71.7% for the 8am–11am slot. By evening the aircraft flying these rotations have absorbed a full day of small delays and there is no slack left to recover in. The 2pm–5pm window is the busiest, with 261 flights scheduled in it.
Across the year
Alaska on ORD to SAN through the year
Delays peak in November, when the on-time rate falls to 50.0%. February is the strongest month at 87.5%. Moving a flexible trip across that boundary buys 38 points. November was the busiest month here, with 88 flights.
Across the week, Saturday is the strongest day at 80.7% on time and Friday the weakest at 56.4%. 24 points is a smaller lever than departure hour, but it is free.
Delay causes
Why Alaska runs late on this route
One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 15,000 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.
- 44%Late-arriving aircraft
- 28%National Airspace System
- 22%Carrier
- 7%Extreme weather
44% of delay minutes trace back to a late-arriving aircraft, meaning the plane was already behind before it got here. That is a cascade, and cascades start small and grow through the day. Across 15,000 reported delay minutes here, that single category outweighs weather by 6 to one. It is the strongest argument for booking the first departure of the morning, when the aircraft has been sitting at the gate overnight with nothing to inherit. The split is drawn from 14,770 reported delay minutes.
The practical consequence: the 8am–11am departure is the one that starts clean. Its aircraft has no earlier leg to be late from, which is exactly why that window shows 71.7% on time here.
Cancellations sit at 2.33% against a national 1.81%, which is ordinary. Diversions add another 0.15%.
Connections and stage length
What a delay here costs
For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 11.3% 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.
At 1,723 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 73.5% on time across 688 flights, 5 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 5 points of difference.
One caution: this is a thin sample. 688 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 Alaska on ORD to SAN
Put together: treat all of this as provisional. 688 flights over twelve months is enough to clear this site's floor and not enough to be confident to better than a couple of points. The 68.4% headline is the most reliable number on the page; the hour and month splits below it are built on a few dozen flights each. 671 completed flights over 12 months sit behind that.
Related
Where to go next
- ORD to SAN, every carrier
- Alaska on SAN to ORD, the return leg
- United Airlines on ORD to SAN77.0%
- American Airlines on ORD to SAN66.3%
- Alaska Airlines network-wide record
- Chicago O'Hare International (ORD) delay statistics
- San Diego International (SAN) delay statistics
- Why the first flight of the morning is statistically safest
- Same route, different airline: where the carrier you pick matters most
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.