Route profile
ORD→SAN
Flight reliability, delays and best times to fly from Chicago to San Diego, 1,723 miles.
Right now
Aviation weather is not currently a factor.
Aviation weather is not currently a factor.
Route reliability
July 2023 – July 2026
Better than 30% of comparable major US routes (4,598 compared)
Calculated from 9,863 flights. How this is calculated · What counts as on time
ORD → SAN arrives on time 74.7% of the time; the return trip, SAN → ORD, arrives on time 81.7% of the time, a 7.0-point gap between the two directions of the same city pair.
ORD → SAN spends 30.5 minutes on the ground on a 1,723-mile trip: 24.7 minutes from pushback to wheels-up at ORD and 5.9 minutes from touchdown to gate at SAN.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What stands out
On-time performance swings unusually widely by time of day here, wider than 92% of 4,023 comparable routes.
87.1% on time for 5–9 AM departures, against 55.7% for 9 PM–5 AM.
Source: FlyerIntel analysis of US DOT BTS data · July 2023 – July 2026 · Ranked against every other route with the same kind of figure and at least 4,023 in the comparison.
What sets this route apart
Where ORD to SAN differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
ORD to SAN struggles most at 9 PM: 55.7% of its flights scheduled then arrive on time, 12.1 points behind the 67.8% on routes of similar length at the same hour. Against all other routes the gap is 13.8 points.
ORD to SAN is at its best against routes of similar length for flights scheduled at 1 PM: 80.4% arrive on time, 5.9 points ahead of the 74.5% those routes manage at that hour. Against all other routes the gap is 3.3 points.
Friday is the day ORD to SAN slips furthest against routes of similar length, 70.2% on time where they average 76.3%, 6.1 points lower. Against all other routes the gap is 6 points.
In April, ORD to SAN runs 7.1 points below routes of similar length, 72.6% on time to 79.7%. Against all other routes the gap is 7.3 points.
Alaska Airlines’ flights on ORD to SAN arrive on time 68.7% of the time, 8.3 points below the 77.0% it manages on its routes of similar length. Against all other routes the gap is 9.3 points.
ORD to SAN against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 9 PM departures | 55.7% | routes of similar length | 67.8% | −12.1 pts | 418 here, 31,338 there |
| Hour: 1 PM departures | 80.4% | routes of similar length | 74.5% | +5.9 pts | 913 here, 75,363 there |
| Weekday: Friday | 70.2% | routes of similar length | 76.3% | −6.1 pts | 1,441 here, 208,637 there |
| Month: April | 72.6% | routes of similar length | 79.7% | −7.1 pts | 826 here, 113,344 there |
| Airline: Alaska Airlines | 68.7% | routes of similar length | 77.0% | −8.3 pts | 758 here, 88,150 there |
Each comparison pools the flights of other routes, with this route’s own left out. Similar length means within 15% of this route’s 1,723 miles, with at least 5 such routes. A bucket is set against the most comparable group that has enough flights: similar length, then the same origin (at least 3 routes), then all other routes. Hours, weekdays and months appear only where both sides have 120 completed flights, and airlines where both have 600. The gap must be at least 2 points and 2 standard errors, and only the largest gap each way is kept per measure. These are differences in the flights counted, not causes.
Why ORD → SAN flights are cancelled
July 2023 – July 2026
ORD → SAN cancelled 105 of 9,863 scheduled flights — about 1 in every 94. The reason filed most often was extreme weather, 46.7% of the cancellations coded on this route — about 1 in every 201 scheduled flights.
Share of cancellations
Of 105 cancelled departures carrying a reason code.
What each reason means
Conditions the carrier judged severe enough to stop the flight: a blizzard, a hurricane, a line of thunderstorms.
49 cancellations, 46.7% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
45 cancellations, 42.9% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
11 cancellations, 10.5% of the total.
A terminal evacuation, a security breach, screening equipment failure, or screening queues over 29 minutes.
0 cancellations, 0.0% of the total.
Reason codes are the operating airline’s own filing with US DOT, not an independent finding of fault. Ordinary bad weather is filed under air traffic, so weather’s full share is larger than its bar.
105 coded cancellations were recorded on ORD → SAN; the section appears from 50.
When it goes wrong
July 2023 – July 2026
55 min late
against a median of 4 min early
Percentiles over 9,863 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at SAN after arriving from ORD.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 42% | Likely to miss |
| 45 min | 24% | High risk |
| 60 min | 16% | High risk |
| 90 min | 9.1% | Some risk |
| 120 min | 5.5% | Some risk |
This is one leg of a connection. Gate changes and the next flight's own schedule matter too. And a connection can fail before delay is even the question — this route cancels 1.06% of the time and diverts 0.35% of the time, which a late arrival never shows up in.
Chance of missing is the share of 9,723 arrivals on this route that landed later than the connection time less 30 minutes to reach the next gate.
The worst tenth of arrivals on this route land at least 55 minutes late (90th-percentile gate arrival delay), over 9,863 operations.
Any other layover length: connection checker.
Best time to fly
ORD → SAN flights departing 5–9 AM arrived on time 87.1% of the time, against 55.7% for 9 PM–5 AM departures, a gap of 31.4 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 87.9% on time from 182 flights
- 7 AM: 89.3% on time from 998 flights
- 8 AM: 84.4% on time from 901 flights
- 9 AM: 78.2% on time from 969 flights
- 10 AM: 77.4% on time from 773 flights
- 11 AM: 73.0% on time from 336 flights
- 12 PM: too few flights to score
- 1 PM: 80.4% on time from 920 flights
- 2 PM: 70.7% on time from 188 flights
- 3 PM: 69.9% on time from 304 flights
- 4 PM: 72.2% on time from 1,345 flights
- 5 PM: 64.7% on time from 541 flights
- 6 PM: 63.4% on time from 283 flights
- 7 PM: 67.1% on time from 851 flights
- 8 PM: 65.4% on time from 780 flights
- 9 PM: 55.7% on time from 436 flights
- 10 PM to 11 PM: too few flights to score
Why ORD → SAN runs late
July 2023 – July 2026
the inbound aircraft was late, so this flight started late
crew, maintenance, boarding and fueling, all within the carrier’s control
airspace and airport capacity, including weather-driven flow control
weather severe enough to stop this flight specifically
screening or terminal security incidents
Share of the delay minutes US DOT attributed to each cause for ORD → SAN. Only delays of 15 minutes or more are attributed. What the five causes mean
Late-arriving aircraft is the largest cause on ORD → SAN, at 42.8%: flights here mostly leave late because the plane came in late, and the day shows it: 5–9 AM departures arrived on time 87.1% of the time and 9 PM–5 AM departures 55.7%.
Airlines on this route
Carriers with at least 200 flights, by the airline that operated each one.
| Carrier | Flights | On time | Cancelled | Median delay | Severe |
|---|---|---|---|---|---|
| United Airlines | 5,200 | 79.5% | 0.75% | -6 min | 6.9% |
| American Airlines | 3,804 | 70.0% | 1.24% | -2 min | 11.8% |
| Alaska Airlines | 777 | 68.7% | 2.32% | -3 min | 11.1% |
United Airlines flew 53.2% of the 9,781 flights listed. Alaska Airlines cancelled 2.32% of its flights here against 0.75% for United Airlines.
United Airlines arrived on time 10.8 percentage points more often than Alaska Airlines on this route.
Flights on this route
Flight numbers with at least 600 operations here and still on the schedule.
| Flight | Scheduled | Operations | On time |
|---|---|---|---|
| UA2683 United Airlines | 1:15 PM | 871 | 83.2% |
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Friday the least, a gap of 8.5 percentage points.
By month
- Jan: 76.9%
- Feb: 78.5%
- Mar: 80.0%
- Apr: 72.6%
- May: 75.3%
- Jun: 68.4%
- Jul: 68.2%
- Aug: 72.6%
- Sep: 79.6%
- Oct: 80.0%
- Nov: 77.0%
- Dec: 74.7%
July is historically the weakest month and March the strongest, a spread of 11.8 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 65.3% from 226 flights
- August 2023: 75.5% from 235 flights
- September 2023: 81.7% from 231 flights
- October 2023: 86.0% from 229 flights
- November 2023: 87.2% from 189 flights
- December 2023: 88.7% from 214 flights
- January 2024: 78.7% from 209 flights
- February 2024: 84.9% from 187 flights
- March 2024: 83.6% from 207 flights
- April 2024: 76.1% from 235 flights
- May 2024: 64.9% from 247 flights
- June 2024: 65.4% from 269 flights
- July 2024: 67.1% from 293 flights
- August 2024: 69.0% from 289 flights
- September 2024: 79.7% from 246 flights
- October 2024: 82.1% from 270 flights
- November 2024: 79.4% from 214 flights
- December 2024: 77.0% from 228 flights
- January 2025: 79.7% from 190 flights
- February 2025: 74.3% from 168 flights
- March 2025: 82.8% from 228 flights
- April 2025: 82.0% from 263 flights
- May 2025: 82.6% from 276 flights
- June 2025: 71.6% from 315 flights
- July 2025: 66.0% from 335 flights
- August 2025: 73.6% from 320 flights
- September 2025: 77.8% from 270 flights
- October 2025: 74.4% from 357 flights
- November 2025: 69.0% from 318 flights
- December 2025: 63.1% from 308 flights
- January 2026: 73.3% from 248 flights
- February 2026: 76.3% from 242 flights
- March 2026: 75.7% from 332 flights
- April 2026: 62.8% from 333 flights
- May 2026: 76.9% from 364 flights
- June 2026: 67.8% from 380 flights
- July 2026: 72.4% from 398 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 71.8% against 76.7% in the 12 months before — declining by 4.9 percentage points.
Data and methodology
Calculated by FlyerIntel from 9,863 ORD → SAN flight records from the US DOT Bureau of Transportation Statistics, covering July 2023 – July 2026. Late means 15 or more minutes past scheduled arrival; cancelled and diverted flights are left out of on-time rates.
Full methodology · Data sources · Report a problem
Related research: How Long a Layover Needs to Be · Two Airlines on One Route · Best Time of Day to Fly From Major US Airports
Analysis last recomputed