Route Reliability

Route reliability

San Diego (SAN) to Chicago (ORD): which airline is most on time?

On-time arrivals, cancellations and long delays for every airline that reported nonstop flights from San Diego, CA (SAN) to Chicago, IL (ORD), September 2025 to August 2026.

Historical performance Official DOT data through August 2026 · Not live flight status

San Diego, CAChicago, IL

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Three-letter airport codes, nonstop U.S. domestic flights. One direction at a time.

Route at a glance · September 2025 to August 2026

SAN to ORD

San Diego, CA to Chicago, IL

On time
75.5%vs 75.6% U.S. average About average
Cancelled
1.3%vs 1.9% U.S. average Better than average
60+ min late
7.9%vs 8.1% U.S. average About average
Scheduled flights
3,944in 12 months4 airlines
Most reliable airline
United Airlines78.7% on time · 1,677 flights

On time about as often as the U.S. average, with fewer cancellations.

Compared with all U.S. flights, September 2025 to August 2026. “About average” means within 1.5 points for on time, 0.3 for cancelled and 1 for 60+ minutes late.

Airlines on this route

Ranked by on-time arrival

Airlines from SAN to ORD, September 2025 to August 2026. Rates are shares of all scheduled flights.
Airline On time Cancelled 60+ min late Avg delay when late Diverted Flights
1. United Airlines Most reliable 78.7% 0.5% 6.9% 78 min 1.0% 1,677
2. American Airlines 77.1% 1.6% 7.8% 98 min 1.4% 1,400
3. Alaska Airlines 66.7% 2.6% 10.1% 61 min 1.7% 862
Frontier Airlines Insufficient sample (fewer than 50 flights) 5

On time = arrived within 15 minutes of schedule. Avg delay when late = average arrival delay of flights 15+ minutes late. "Most reliable" needs at least 300 flights in 12 months. Tap a heading to sort.

What this means

United Airlines has the strongest record on this route.

  • United Airlines had the best on-time record from San Diego (SAN) to Chicago (ORD): 78.7% of its 1,677 scheduled flights arrived within 15 minutes of schedule, compared with 66.7% for Alaska Airlines.
  • Frontier Airlines also flew this route but with fewer than 50 reported flights, too few to rate.
  • 1.3% of flights on this route were cancelled (about 1 in 77), 0.6 points lower than the U.S. average of 1.9%.
  • 7.9% of flights, about 1 in 13, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 79 min.
  • Overall, 75.5% of flights on this route arrived on time, about the same as the U.S. average of 75.6%.
  • Over the last 3 years, September was the most reliable month on this route (87.5% on time) and July the least reliable (68.7%).
  • Cancellations peaked in January, when 3.2% of flights were cancelled.
  • Flights scheduled to depart 10 pm to 11 pm were the most punctual (91.7% on time); flights scheduled to depart noon to 1 pm were the least (57.7%).
  • In the other direction, Chicago (ORD) to San Diego (SAN), 69.3% of flights were on time and 1.3% were cancelled. Compare airlines ORD to SAN.

Best and worst months to fly SAN to ORD

Jan 78.2%
Feb 87.1%
Mar 78.6%
Apr 85.0%
May 81.5%
Jun 76.1%
Jul 68.7%
Aug 71.1%
Sep 87.5%
Oct 83.8%
Nov 81.8%
Dec 81.6%
Share of scheduled flights on time 12-month average 75.5%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 78.2% 647
February 87.1% 597
March 78.6% 767
April 85.0% 831
May 81.5% 887
June 76.1% 964
July 68.7% 1,026
August 71.1% 1,004
September 87.5% 746
October 83.8% 856
November 81.8% 720
December 81.6% 750
Best and worst calendar month by airline, September 2023 to August 2026.
AirlineBest monthWorst month
United Airlines September (89.7%) July (69.8%)
American Airlines September (84.8%) July (73.2%)
Alaska Airlines February (91.1%) August (43.5%)

Month by month, last 12 months

Sep 82.5%
Oct 82.1%
Nov 71.1%
Dec 75.4%
Jan 75.7%
Feb 85.5%
Mar 70.5%
Apr 77.5%
May 82.4%
Jun 73.9%
Jul 70.1%
Aug 65.3%
Share of scheduled flights on time U.S. average 75.6%
All airlines combined, September 2025 to August 2026. Scale starts at zero.
Show as table
PeriodOn timeFlights
Sep 2025 82.5% 269
Oct 2025 82.1% 357
Nov 2025 71.1% 318
Dec 2025 75.4% 309
Jan 2026 75.7% 247
Feb 2026 85.5% 242
Mar 2026 70.5% 332
Apr 2026 77.5% 333
May 2026 82.4% 364
Jun 2026 73.9% 380
Jul 2026 70.1% 398
Aug 2026 65.3% 395

Best and worst departure times

6a 85.4%
7a 80.7%
8a 72.7%
9a 78.1%
10a 78.1%
11a Insufficient sample
12p 57.7%
1p 62.9%
2p 64.2%
3p 65.9%
4p 69.1%
5p 73.4%
10p 91.7%
Share of scheduled flights on time
By scheduled local departure hour at SAN, September 2025 to August 2026. Hours with no scheduled flights are omitted. Scale starts at zero.
Show as table
PeriodOn timeFlights
Departing 6 am to 7 am 85.4% 547
Departing 7 am to 8 am 80.7% 429
Departing 8 am to 9 am 72.7% 165
Departing 9 am to 10 am 78.1% 73
Departing 10 am to 11 am 78.1% 425
Departing 11 am to noon Insufficient sample 38
Departing noon to 1 pm 57.7% 168
Departing 1 pm to 2 pm 62.9% 431
Departing 2 pm to 3 pm 64.2% 402
Departing 3 pm to 4 pm 65.9% 167
Departing 4 pm to 5 pm 69.1% 175
Departing 5 pm to 6 pm 73.4% 428
Departing 10 pm to 11 pm 91.7% 496
Woman at an airport window watching a plane take off
Photo: Depositphotos (licensed stock, illustrative only). Credits

Sources & data dates

Source
U.S. DOT Bureau of Transportation Statistics, Reporting Carrier On-Time Performance (1987-present)
Period
September 2025 to August 2026 (12 months); month-of-year patterns September 2023 to August 2026
Data through
August 2026
Processed
2026-11-03
Scope
Nonstop scheduled flights from San Diego, CA (SAN) to Chicago, IL (ORD), one direction. Airlines that report to the DOT only.
Method
Rates use all scheduled flights as the denominator; cancelled and diverted flights count as not on time. Figures based on fewer than 50 scheduled flights are suppressed. Full methodology.

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