Route profile
SAN→ORD
Flight reliability, delays and best times to fly from San Diego to Chicago, 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 61% of comparable major US routes (4,598 compared)
Calculated from 9,861 flights. How this is calculated
SAN → ORD arrives on time 81.7% of the time; the return trip, ORD → SAN, arrives on time 74.7% of the time, a 7.0-point gap between the two directions of the same city pair.
SAN → ORD spends 37.8 minutes on the ground on a 1,723-mile trip: 22.3 minutes from pushback to wheels-up at SAN and 15.5 minutes from touchdown to gate at ORD.
Source: US DOT Bureau of Transportation Statistics · Data covering July 2023 – July 2026
What sets this route apart
Where SAN to ORD differs most from similar routes by hour, weekday, month and airline, July 2023 – July 2026.
SAN to ORD is at its best against routes of similar length for flights scheduled at 10 PM: 93.7% arrive on time, 19.5 points ahead of the 74.2% those routes manage at that hour. Against all other routes the gap is 22.2 points.
SAN to ORD struggles most at 12 PM: 65.8% of its flights scheduled then arrive on time, 11.7 points behind the 77.5% on routes of similar length at the same hour. Against all other routes the gap is 13.6 points.
SAN to ORD holds up on Saturdays better than routes of similar length do: 85.3% on time to their 78.6%, a 6.7 points lead. Against all other routes the gap is 6.2 points.
May is kinder to SAN to ORD than to routes of similar length: 82.5% on time against 75.2%, 7.3 points better. Against all other routes the gap is 7.3 points.
American Airlines does better on SAN to ORD than on its routes of similar length: 81.3% on time here, 76.1% there, 5.2 points apart. Against all other routes the gap is 6.2 points.
SAN to ORD against comparable routes
July 2023 – July 2026| Measure | This route | Compared with | Them | Gap | Flights behind it |
|---|---|---|---|---|---|
| Hour: 10 PM departures | 93.7% | routes of similar length | 74.2% | +19.5 pts | 1,805 here, 30,607 there |
| Hour: 12 PM departures | 65.8% | routes of similar length | 77.5% | −11.7 pts | 269 here, 78,156 there |
| Weekday: Saturday | 85.3% | routes of similar length | 78.6% | +6.7 pts | 1,293 here, 188,941 there |
| Month: May | 82.5% | routes of similar length | 75.2% | +7.3 pts | 876 here, 119,971 there |
| Airline: American Airlines | 81.3% | routes of similar length | 76.1% | +5.2 pts | 3,726 here, 241,620 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 SAN → ORD flights are cancelled
July 2023 – July 2026
SAN → ORD cancelled 113 of 9,861 scheduled flights — about 1 in every 87. The reason filed most often was extreme weather, 46.9% of the cancellations coded on this route — about 1 in every 186 scheduled flights.
Share of cancellations
Of 113 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.
53 cancellations, 46.9% of the total.
Crew, maintenance, aircraft cleaning, baggage or fueling: what BTS counts as within the carrier’s own control.
47 cancellations, 41.6% of the total.
Airport capacity, air traffic control flow programs, heavy traffic and ordinary bad weather. A system decision, not the airline’s.
13 cancellations, 11.5% 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.
113 coded cancellations were recorded on SAN → ORD; the section appears from 50.
When it goes wrong
July 2023 – July 2026
36 min late
against a median of 9 min early
Percentiles over 9,861 operations; cancelled and diverted flights are counted separately.
Will your connection be tight enough?
Layovers at ORD after arriving from SAN.
| Connection time | Chance of missing | Reads as |
|---|---|---|
| 30 min | 33% | Likely to miss |
| 45 min | 18% | High risk |
| 60 min | 11% | Some risk |
| 90 min | 6.2% | Some risk |
| 120 min | 4.1% | Low 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 1.15% of the time and diverts 0.77% of the time, which a late arrival never shows up in.
Chance of missing is the share of 9,672 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 36 minutes late (90th-percentile gate arrival delay), over 9,861 operations.
Any other layover length: connection checker.
Best time to fly
SAN → ORD flights departing 9 PM–5 AM arrived on time 93.7% of the time, against 69.5% for 12–3 PM departures, a gap of 24.2 percentage points.
By departure window
By departure hour
- 12 AM to 5 AM: too few flights to score
- 6 AM: 88.7% on time from 1,490 flights
- 7 AM: 87.2% on time from 868 flights
- 8 AM: 78.5% on time from 260 flights
- 9 AM: too few flights to score
- 10 AM: 82.8% on time from 1,196 flights
- 11 AM: 75.6% on time from 464 flights
- 12 PM: 65.8% on time from 278 flights
- 1 PM: 66.9% on time from 903 flights
- 2 PM: 72.6% on time from 1,075 flights
- 3 PM: 71.4% on time from 207 flights
- 4 PM: 74.0% on time from 545 flights
- 5 PM: 81.2% on time from 661 flights
- 6 PM to 9 PM: too few flights to score
- 10 PM: 93.7% on time from 1,826 flights
- 11 PM: too few flights to score
Departure windows with fewer than 120 flights are not scored.
Why SAN → ORD 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 SAN → ORD. Only delays of 15 minutes or more are attributed.
Late-arriving aircraft is the largest cause on SAN → ORD, at 37.5%: flights here mostly leave late because the plane came in late, and the day shows it: 9 PM–5 AM departures arrived on time 93.7% of the time and 12–3 PM departures 69.5%.
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 | 84.2% | 0.88% | -9 min | 5.1% |
| American Airlines | 3,804 | 81.3% | 1.24% | -10 min | 6.9% |
| Alaska Airlines | 777 | 72.0% | 2.32% | -3 min | 9.8% |
United Airlines flew 53.2% of the 9,781 flights listed. Alaska Airlines cancelled 2.32% of its flights here against 0.88% for United Airlines.
United Airlines arrived on time 12.2 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.
Weekly and seasonal patterns
By day of week
Saturday is historically the most reliable day and Sunday the least, a gap of 7.2 percentage points.
By month
- Jan: 81.1%
- Feb: 87.4%
- Mar: 80.7%
- Apr: 86.0%
- May: 82.5%
- Jun: 77.4%
- Jul: 73.3%
- Aug: 80.5%
- Sep: 87.8%
- Oct: 84.6%
- Nov: 83.3%
- Dec: 82.7%
July is historically the weakest month and September the strongest, a spread of 14.5 percentage points.
Reliability over time
July 2023 – July 2026
- July 2023: 80.3% from 226 flights
- August 2023: 89.1% from 235 flights
- September 2023: 92.6% from 231 flights
- October 2023: 87.2% from 229 flights
- November 2023: 93.1% from 189 flights
- December 2023: 90.6% from 213 flights
- January 2024: 86.5% from 210 flights
- February 2024: 93.0% from 187 flights
- March 2024: 88.9% from 207 flights
- April 2024: 88.5% from 235 flights
- May 2024: 76.3% from 247 flights
- June 2024: 80.9% from 269 flights
- July 2024: 70.1% from 292 flights
- August 2024: 82.8% from 289 flights
- September 2024: 88.6% from 246 flights
- October 2024: 84.3% from 270 flights
- November 2024: 87.8% from 213 flights
- December 2024: 82.3% from 228 flights
- January 2025: 80.4% from 190 flights
- February 2025: 83.3% from 168 flights
- March 2025: 81.5% from 228 flights
- April 2025: 92.7% from 263 flights
- May 2025: 86.6% from 276 flights
- June 2025: 75.5% from 315 flights
- July 2025: 71.3% from 336 flights
- August 2025: 72.1% from 320 flights
- September 2025: 82.8% from 269 flights
- October 2025: 83.0% from 357 flights
- November 2025: 74.1% from 318 flights
- December 2025: 77.4% from 309 flights
- January 2026: 77.3% from 247 flights
- February 2026: 85.9% from 242 flights
- March 2026: 74.8% from 332 flights
- April 2026: 78.9% from 333 flights
- May 2026: 83.6% from 364 flights
- June 2026: 76.6% from 380 flights
- July 2026: 73.2% from 398 flights
Over the most recent 12 months (2025-08 to 2026-07), on-time arrivals averaged 78.1% against 82.7% in the 12 months before — declining by 4.6 percentage points.
Data and methodology
Calculated by FlyerIntel from 9,861 SAN → ORD 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