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DelayAtlas

Airport month record

SANDEC

San Diego International in December 2025

Departures
8,228
Month
December 2025
National, same month
73.2%
Carriers
9
BGRADE

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

SAN in December sits in the middle of the pack with a B. Close to three flights in four arrive on time by the DOT's definition, 2 points better than the national rate of 73.2%. The late ones land about an hour behind schedule. That rests on 8,228 flights, of which American Airlines flew 722 at 83.4% on time.

American Airlines is the most reliable of the six carriers covered here at 83.4% on time across 722 flights.

Key figures

On time

75.4%

Arrivals under 15 minutes late, of 8,073 completed departures

Avg delay

63 min

Across delayed arrivals only, not all flights

Cancelled

1.42%

Nationally in December: 1.55%

Whole year

78.0%

SAN across all twelve months

These figures cover 8,228 departures from San Diego International in December 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

December next to SAN's other months

Against SAN's own year, December ran 3 points worse than the twelve-month rate of 78.0%, which makes it number ten of twelve months, best first. Either side of it, November ran 77.1% on time and January 83.1%, so a trip moved by a few weeks would have landed in a better stretch.

SAN month by month
MonthFlightsOn timeAvg delayCancelledGrade
July 20258,77673.9%62 min1.32%C
August 20258,40676.7%58 min0.75%B+
September 20257,87581.9%74 min1.37%B
October 20258,68779.0%63 min0.92%B+
November 20258,24677.1%65 min2.81%B
December 2025 (this page)8,22875.4%63 min1.42%B
January 20267,40683.1%79 min2.71%B
February 20267,00884.0%64 min0.97%B+
March 20268,54778.2%64 min1.03%B
April 20268,50580.8%54 min0.33%B+
May 20268,94776.9%54 min0.66%B+
June 20268,99671.1%55 min1.00%C

Departure window

The best time of day to leave SAN in December

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 25 points, against 11 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

  • 5am–8am1,203 flights90.9%
  • 8am–11am1,736 flights79.9%
  • 11am–2pm1,635 flights72.2%
  • 2pm–5pm1,301 flights66.0%
  • 5pm–8pm1,167 flights68.0%
  • 8pm–5am1,186 flights75.2%

Scale runs 60% to 95%. Rows with fewer than 30 flights show a dash.

Book the early departure. Flights leaving between 5am–8am arrive on time 90.9% of the time, against 66.0% for the afternoon window. That is 25 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 1,736 flights scheduled in it.

Across the week, Thursday is the strongest day at 81.1% on time and Friday the weakest at 66.7%. 14 points is a smaller lever than departure hour, but it is free.

On-time rate by day of the week79.2Mon78.2Tue72.4Wed81.1Thu66.7Fri76.6Sat72.6Sun
Monday: 79.2 percent on time. Tuesday: 78.2 percent on time. Wednesday: 72.4 percent on time. Thursday: 81.1 percent on time. Friday: 66.7 percent on time. Saturday: 76.6 percent on time. Sunday: 72.6 percent on time

Carrier by carrier

Which airlines ran best at SAN in December

The choice of carrier is not cosmetic here. American Airlines arrives on time 83.4% of the time; Southwest Airlines manages 72.5%. Sample sizes sit next to every figure, because a two-point gap across 3,202 flights means less than a ten-point one.

Carriers at SAN in December 2025
AirlineFlightsOn timeAvg delayCancelledGrade
Southwest Airlines3,20272.5%51 min1.06%C
SkyWest Airlines1,18172.8%64 min2.37%C
Alaska Airlines1,07072.8%62 min1.78%C
United Airlines84281.0%73 min0.36%B+
Delta Air Lines83581.5%83 min2.28%B
American Airlines72283.4%84 min0.42%B+
Frontier Airlinesthin sample17669.2%84 min2.27%C
JetBlue Airwaysthin sample12084.5%67 min3.33%B−
Hawaiian Airlinesthin sample8066.7%142 min3.75%C−

American leads Southwest by 11 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 December

Routes from SAN in December 2025
RouteFlightsOn timeAvg delayCancelledGrade
SAN to DEN · Denver53773.0%61 min1.30%C
SAN to SFO · San Francisco48568.3%75 min1.03%C
SAN to LAS · Las Vegas47573.5%58 min0.84%C+
SAN to PHX · Phoenix46378.4%61 min1.08%B
SAN to SMF · Sacramento39870.3%45 min1.76%C
SAN to SJC · San Jose39773.2%53 min1.26%C
SAN to SEA · Seattlethin sample35577.1%68 min2.82%B
SAN to ORD · Chicagothin sample30977.4%54 min2.27%B
SAN to DFW · Dallas-Fort Worththin sample28179.4%69 min0.00%B+
SAN to SLC · Salt Lake Citythin sample27581.3%63 min0.36%B+
SAN to OAK · Oaklandthin sample26270.5%55 min1.53%C
SAN to ATL · Atlantathin sample21578.8%82 min0.93%B+
SAN to JFK · New Yorkthin sample21283.0%82 min4.25%B−
SAN to AUS · Austinthin sample19864.6%56 min1.52%D
SAN to LAX · Los Angelesthin sample18879.1%69 min0.53%B+
SAN to FAT · Fresnothin sample16375.3%43 min3.07%B−
SAN to PDX · Portlandthin sample15681.9%43 min0.64%B+
SAN to HNL · Honoluluthin sample15668.7%111 min3.21%C−
SAN to IAH · Houstonthin sample14586.2%62 min0.00%A+
SAN to DAL · Dallasthin sample13770.8%47 min0.00%C+
SAN to BOS · Bostonthin sample13476.0%65 min2.24%B
SAN to RNO · Renothin sample13176.4%50 min1.53%B
SAN to EWR · Newarkthin sample12477.5%101 min1.61%B
SAN to IAD · Washingtonthin sample12290.2%87 min0.00%A+
SAN to MSP · Minneapolisthin sample11977.1%119 min0.84%B+

Delay causes

What held SAN up in December

One category carries most of the weight here. Late-arriving aircraft accounts for 55% of the 125,000 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
    55%
  • Carrier
    23%
  • National Airspace System
    15%
  • Extreme weather
    7%
  • Security
    0%

55% 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 125,000 reported delay minutes here, that single category outweighs weather by 8 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 125,189 reported delay minutes.

Cancellations sit at 1.42% against a national 1.55%, which is ordinary. Diversions add another 0.46%.

7.9% of arrivals land an hour or more late, close to the national 10.0%. 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 about an hour, which a normal layover absorbs.

What to do with this

Flying from SAN in December

For a December trip through SAN: plan on this being one of the airport's harder months. The 5am–8am departures held up best at 90.9% on time, and with 7.9% of arrivals an hour or more late, a connection here deserves more slack than the same trip in February would.

Related

Where to go next

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.