Airport month record

SANSEP

San Diego International in September 2025

Departures: 7,875
Month: September 2025
National, same month: 83.4%
Carriers: 10

Historical statistics for September 2025, not live status or a forecast for this year’s September. For today’s conditions at SAN, see live FAA status.

SAN in September lands a B, 2 points worse than the national rate of 83.4%. About one flight in six arrives 15 minutes late or worse, and those flights are late by a little over an hour on average. That is a workable record, not a spotless one. That rests on 7,875 flights, of which Delta Air Lines flew 786 at 87.9% on time.

Delta Air Lines is the most reliable of the six carriers covered here at 87.9% on time across 786 flights.

On time

81.9%

Arrivals under 15 minutes late, of 7,748 completed departures

Avg delay

74 min

Across delayed arrivals only, not all flights

Cancelled

1.37%

Nationally in September: 0.51%

Whole year

78.0%

SAN across all twelve months

These figures cover 7,875 departures from San Diego International in September 2025. On time means an arrival less than 15 minutes after the scheduled gate time, the DOT's threshold, and the national comparison uses every US departure in the same month rather than the whole year.

Against the year

September next to SAN's other months

Against SAN's own year, September ran 4 points better than the twelve-month rate of 78.0%, which makes it number three of twelve months, best first. Either side of it, August ran 76.7% on time and October 79.0%, so a trip moved by a few weeks would have landed in a worse stretch.

SAN month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	8,776	73.9%	62 min	1.32%	C
August 2025	8,406	76.7%	58 min	0.75%	B+
September 2025 (this page)	7,875	81.9%	74 min	1.37%	B
October 2025	8,687	79.0%	63 min	0.92%	B+
November 2025	8,246	77.1%	65 min	2.81%	B
December 2025	8,228	75.4%	63 min	1.42%	B
January 2026	7,406	83.1%	79 min	2.71%	B
February 2026	7,008	84.0%	64 min	0.97%	B+
March 2026	8,547	78.2%	64 min	1.03%	B
April 2026	8,505	80.8%	54 min	0.33%	B+
May 2026	8,947	76.9%	54 min	0.66%	B+
June 2026	8,996	71.1%	55 min	1.00%	C

Departure window

The best time of day to leave SAN in September

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 18 points, against 10 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,211 flights91.7%
8am–11am1,705 flights86.0%
11am–2pm1,538 flights80.6%
2pm–5pm1,208 flights73.5%
5pm–8pm1,145 flights76.0%
8pm–5am1,068 flights81.6%

Scale runs 65% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 91.7% of the time, against 73.5% for the afternoon window. That is 18 points of difference for no extra money, and it comes from the same aircraft having had no earlier flight to fall behind on. The 8am–11am window is the busiest, with 1,705 flights scheduled in it.

Across the week, Saturday is the strongest day at 90.0% on time and Thursday the weakest at 65.4%. 25 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at SAN in September

The choice of carrier is not cosmetic here. Delta Air Lines arrives on time 87.9% of the time; Southwest Airlines manages 78.1%. Sample sizes sit next to every figure, because a two-point gap across 2,856 flights means less than a ten-point one.

Carriers at SAN in September 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
Southwest Airlines	2,856	78.1%	62 min	1.09%	B
SkyWest Airlines	1,145	84.2%	56 min	1.92%	B
Alaska Airlines	970	82.5%	60 min	1.96%	B
United Airlines	886	85.4%	68 min	1.35%	A
Delta Air Lines	786	87.9%	94 min	0.76%	A+
American Airlines	725	84.0%	146 min	1.24%	B
Frontier Airlinesthin sample	202	78.9%	130 min	0.99%	B+
JetBlue Airwaysthin sample	118	80.7%	144 min	2.54%	B
Spirit Airlinesthin sample	105	86.1%	84 min	3.81%	A−
Hawaiian Airlinesthin sample	81	63.0%	64 min	0.00%	D+

Delta leads Southwest by 10 points. Real, but small enough that a better departure time on the weaker carrier can outweigh it.

Route by route

Busiest routes out of SAN in September

Routes from SAN in September 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
SAN to LAS · Las Vegas	610	78.8%	79 min	1.64%	B
SAN to SFO · San Francisco	581	73.3%	54 min	1.89%	C
SAN to PHX · Phoenix	500	80.4%	96 min	2.80%	B
SAN to SMF · Sacramento	416	81.3%	54 min	0.96%	B+
SAN to DEN · Denver	411	78.1%	64 min	0.73%	B+
SAN to SJC · San Jose	398	80.1%	60 min	1.51%	B
SAN to SEA · Seattle	388	85.1%	93 min	1.29%	A
SAN to OAK · Oaklandthin sample	274	73.9%	56 min	0.73%	C+
SAN to ORD · Chicagothin sample	269	82.8%	70 min	0.37%	B+
SAN to DFW · Dallas-Fort Worththin sample	265	80.3%	95 min	2.64%	B
SAN to ATL · Atlantathin sample	217	88.9%	81 min	0.00%	A+
SAN to LAX · Los Angelesthin sample	209	89.4%	63 min	0.96%	A+
SAN to JFK · New Yorkthin sample	206	89.4%	124 min	2.43%	A
SAN to SLC · Salt Lake Citythin sample	180	86.5%	50 min	1.11%	A
SAN to AUS · Austinthin sample	176	86.7%	69 min	1.14%	A
SAN to EWR · Newarkthin sample	143	85.4%	66 min	2.10%	A
SAN to HNL · Honoluluthin sample	141	74.3%	65 min	0.71%	C+
SAN to IAH · Houstonthin sample	137	88.2%	90 min	0.73%	A+
SAN to BOS · Bostonthin sample	135	72.7%	130 min	1.48%	C
SAN to PDX · Portlandthin sample	130	87.6%	62 min	0.77%	A+
SAN to CLT · Charlottethin sample	119	88.1%	320 min	0.84%	A+
SAN to DTW · Detroitthin sample	119	86.3%	59 min	1.68%	A
SAN to IAD · Washingtonthin sample	119	94.9%	74 min	0.84%	A+
SAN to DAL · Dallasthin sample	116	83.2%	49 min	0.86%	B+
SAN to FAT · Fresnothin sample	107	80.0%	56 min	1.87%	B

Delay causes

What held SAN up in September

One category carries most of the weight here. Late-arriving aircraft accounts for 51% of the 104,000 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.

Late-arriving aircraft
51%
Carrier
24%
National Airspace System
21%
Extreme weather
5%
Security
0%

51% 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 104,000 reported delay minutes here, that single category outweighs weather by 11 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 103,789 reported delay minutes.

Cancellations sit at 1.37% against a national 0.51%, which is ordinary. Diversions add another 0.24%.

6.2% of arrivals land an hour or more late, close to the national 5.4%. That is the figure that decides a connection, and it says a 60 to 75 minute layover is reasonable here while anything under 45 minutes is a bet. Most delays on this route last a little over an hour, which a normal layover absorbs.

What to do with this

Flying from SAN in September

For a September trip through SAN: this is one of the better months to be flying from here, 81.9% on time with 1.37% cancelled. That is a base rate for the month as a whole; a single storm can still spoil a particular day.

San Diego International (SAN), the whole year
SAN in July73.9%
SAN in August76.7%
SAN in October79.0%
SAN in November77.1%
SAN in December75.4%
SAN in January83.1%
SAN in February84.0%
SAN in March78.2%
SAN in April80.8%
SAN in May76.9%
SAN in June71.1%

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.

Key figures