Route Reliability

Route reliability

San Diego (SAN) to Salt Lake City (SLC): 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 Salt Lake City, UT (SLC), September 2025 to August 2026.

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

San Diego, CASalt Lake City, UT

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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 SLC

San Diego, CA to Salt Lake City, UT

On time
82.3%vs 75.6% U.S. average Better than average
Cancelled
0.7%vs 1.9% U.S. average Better than average
60+ min late
5.7%vs 8.1% U.S. average Better than average
Scheduled flights
3,100in 12 months4 airlines
Most reliable airline
Delta Air Lines87.1% on time · 1,739 flights

On time more often than 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 SLC, 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. Delta Air Lines Most reliable 87.1% 0.9% 4.1% 71 min 0.2% 1,739
2. Frontier Airlines Small sample (under 300 flights) 84.1% 0.9% 6.5% 101 min 0.0% 107
3. SkyWest Airlines Operating carrier; sold as United Express, Delta Connection, American Eagle, Alaska 77.0% 0.6% 8.8% 62 min 0.1% 818
4. Southwest Airlines 72.5% 0.2% 6.0% 45 min 0.2% 436

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

Delta Air Lines has the strongest record on this route.

  • Delta Air Lines had the best on-time record from San Diego (SAN) to Salt Lake City (SLC): 87.1% of its 1,739 scheduled flights arrived within 15 minutes of schedule, compared with 72.5% for Southwest Airlines.
  • 0.7% of flights on this route were cancelled (about 1 in 143), 1.2 points lower than the U.S. average of 1.9%.
  • 5.7% of flights, about 1 in 18, arrived an hour or more late. When a flight was late (15+ minutes), the average arrival delay was 63 min.
  • Overall, 82.3% of flights on this route arrived on time, 6.7 points higher than the U.S. average of 75.6%.
  • Over the last 3 years, April was the most reliable month on this route (87.5% on time) and August the least reliable (76.9%).
  • Flights scheduled to depart 6 am to 7 am were the most punctual (95.3% on time); flights scheduled to depart 3 pm to 4 pm were the least (60.1%).
  • In the other direction, Salt Lake City (SLC) to San Diego (SAN), 79.9% of flights were on time and 0.9% were cancelled. Compare airlines SLC to SAN.

Best and worst months to fly SAN to SLC

Jan 83.3%
Feb 85.6%
Mar 84.4%
Apr 87.5%
May 84.5%
Jun 79.4%
Jul 77.7%
Aug 76.9%
Sep 85.6%
Oct 82.8%
Nov 86.5%
Dec 83.4%
Share of scheduled flights on time 12-month average 82.3%
All airlines combined, by calendar month, September 2023 to August 2026 (3 years pooled). Scale starts at zero.
Show as table
PeriodOn timeFlights
January 83.3% 683
February 85.6% 652
March 84.4% 762
April 87.5% 720
May 84.5% 660
June 79.4% 689
July 77.7% 734
August 76.9% 746
September 85.6% 555
October 82.8% 633
November 86.5% 636
December 83.4% 711
Best and worst calendar month by airline, September 2023 to August 2026.
AirlineBest monthWorst month
Delta Air Lines February (90.5%) July (79.8%)
SkyWest Airlines April (87.3%) October (69.0%)
Southwest Airlines September (84.4%) June (63.4%)

Month by month, last 12 months

Sep 85.6%
Oct 85.3%
Nov 82.5%
Dec 80.7%
Jan 83.3%
Feb 86.5%
Mar 86.1%
Apr 87.9%
May 82.5%
Jun 81.1%
Jul 80.1%
Aug 68.7%
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 85.6% 180
Oct 2025 85.3% 238
Nov 2025 82.5% 268
Dec 2025 80.7% 275
Jan 2026 83.3% 252
Feb 2026 86.5% 259
Mar 2026 86.1% 294
Apr 2026 87.9% 272
May 2026 82.5% 240
Jun 2026 81.1% 254
Jul 2026 80.1% 271
Aug 2026 68.7% 297

Best and worst departure times

6a 95.3%
7a Insufficient sample
8a 88.8%
9a 90.3%
10a 92.5%
11a 81.1%
12p Insufficient sample
1p 81.6%
2p Insufficient sample
3p 60.1%
4p 66.7%
5p 75.9%
6p 65.6%
7p 84.6%
8p 71.8%
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 95.3% 387
Departing 7 am to 8 am Insufficient sample 38
Departing 8 am to 9 am 88.8% 196
Departing 9 am to 10 am 90.3% 472
Departing 10 am to 11 am 92.5% 53
Departing 11 am to noon 81.1% 53
Departing noon to 1 pm Insufficient sample 37
Departing 1 pm to 2 pm 81.6% 429
Departing 2 pm to 3 pm Insufficient sample 12
Departing 3 pm to 4 pm 60.1% 178
Departing 4 pm to 5 pm 66.7% 75
Departing 5 pm to 6 pm 75.9% 635
Departing 6 pm to 7 pm 65.6% 93
Departing 7 pm to 8 pm 84.6% 357
Departing 8 pm to 9 pm 71.8% 85
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 Salt Lake City, UT (SLC), 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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