Airport month record

SFODEC

San Francisco International in December 2025

Departures: 11,975
Month: December 2025
National, same month: 73.2%
Carriers: 9

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

SFO in December lands a B, 3 points better than the national rate of 73.2%. About one flight in four 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 11,975 flights, of which American Airlines flew 884 at 82.6% on time.

American Airlines is the most reliable of the six carriers covered here at 82.6% on time across 884 flights.

On time

76.3%

Arrivals under 15 minutes late, of 11,812 completed departures

Avg delay

81 min

Across delayed arrivals only, not all flights

Cancelled

1.07%

Nationally in December: 1.55%

Whole year

77.3%

SFO across all twelve months

These figures cover 11,975 departures from San Francisco 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 SFO's other months

Against SFO's own year, December ran about a point worse than the twelve-month rate of 77.3%, which makes it number eight of twelve months, best first. Either side of it, November ran 78.6% on time and January 82.5%, so a trip moved by a few weeks would have landed in a better stretch.

SFO month by month
Month	Flights	On time	Avg delay	Cancelled	Grade
July 2025	12,958	73.9%	67 min	1.14%	C
August 2025	12,594	79.6%	66 min	0.64%	B+
September 2025	11,830	82.4%	58 min	0.25%	B+
October 2025	12,774	80.1%	61 min	0.36%	B+
November 2025	12,022	78.6%	66 min	1.86%	B
December 2025 (this page)	11,975	76.3%	81 min	1.07%	B
January 2026	11,113	82.5%	85 min	2.43%	B
February 2026	10,316	81.7%	77 min	1.21%	B
March 2026	12,171	84.0%	72 min	1.02%	B
April 2026	12,401	74.7%	63 min	0.70%	C+
May 2026	13,114	70.1%	64 min	0.79%	C+
June 2026	13,415	67.1%	67 min	0.70%	C+

Departure window

The best time of day to leave SFO in December

Departure time matters more here than the choice of carrier. The gap between the best and worst window is 22 points, against 22 points between the best and worst carrier. Each bar is the on-time rate for flights scheduled inside that window.

5am–8am1,740 flights89.7%
8am–11am2,557 flights80.7%
11am–2pm2,271 flights72.0%
2pm–5pm1,751 flights67.5%
5pm–8pm1,469 flights72.4%
8pm–5am2,187 flights74.8%

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 89.7% of the time, against 67.5% for the afternoon window. That is 22 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 2,557 flights scheduled in it.

Across the week, Wednesday is the strongest day at 82.1% on time and Sunday the weakest at 68.6%. 14 points is a smaller lever than departure hour, but it is free.

Carrier by carrier

Which airlines ran best at SFO in December

The choice of carrier is not cosmetic here. American Airlines arrives on time 82.6% of the time; Southwest Airlines manages 60.2%. Sample sizes sit next to every figure, because a two-point gap across 747 flights means less than a ten-point one.

Carriers at SFO in December 2025
Airline	Flights	On time	Avg delay	Cancelled	Grade
United Airlines	4,916	80.6%	63 min	0.16%	B+
SkyWest Airlines	2,793	71.5%	104 min	2.22%	C
Delta Air Lines	1,099	77.6%	81 min	2.18%	B
American Airlines	884	82.6%	109 min	0.68%	B+
Alaska Airlines	849	75.2%	66 min	0.82%	B+
Southwest Airlines	747	60.2%	67 min	0.40%	D+
JetBlue Airwaysthin sample	340	76.7%	100 min	1.47%	B
Frontier Airlinesthin sample	260	67.9%	84 min	3.08%	C−
Hawaiian Airlinesthin sample	86	82.3%	56 min	5.81%	B−

The spread between American and Southwest is 22 points, wide enough that it should decide the booking. On a hundred trips that is 22 more arrivals inside the on-time window.

Route by route

Busiest routes out of SFO in December

Routes from SFO in December 2025
Route	Flights	On time	Avg delay	Cancelled	Grade
SFO to LAX · Los Angeles	846	71.2%	67 min	0.59%	C+
SFO to SEA · Seattle	559	73.7%	70 min	0.72%	C+
SFO to JFK · New York	536	79.5%	87 min	2.43%	B
SFO to LAS · Las Vegas	511	78.0%	59 min	0.59%	B+
SFO to SAN · San Diego	486	61.2%	71 min	0.62%	D+
SFO to DEN · Denver	456	74.6%	64 min	0.44%	C+
SFO to PHX · Phoenix	425	74.8%	96 min	0.24%	C+
SFO to SNA · Santa Ana	394	78.3%	90 min	2.28%	B
SFO to ORD · Chicago	391	80.4%	69 min	0.77%	B+
SFO to EWR · Newark	366	70.3%	88 min	0.55%	C+
SFO to BOS · Bostonthin sample	356	81.6%	72 min	0.56%	B+
SFO to DFW · Dallas-Fort Worththin sample	339	78.9%	82 min	0.88%	B+
SFO to IAH · Houstonthin sample	311	83.9%	54 min	0.00%	B+
SFO to SLC · Salt Lake Citythin sample	294	71.5%	78 min	1.02%	C
SFO to ATL · Atlantathin sample	271	80.7%	83 min	2.21%	B
SFO to AUS · Austinthin sample	260	74.5%	63 min	0.38%	C+
SFO to BUR · Burbankthin sample	254	70.4%	89 min	1.57%	C
SFO to IAD · Washingtonthin sample	245	86.5%	51 min	0.00%	A+
SFO to PDX · Portlandthin sample	235	78.6%	70 min	0.43%	B+
SFO to HNL · Honoluluthin sample	221	84.7%	84 min	2.26%	B
SFO to PSP · Palm Springsthin sample	199	70.6%	92 min	2.51%	C
SFO to RNO · Renothin sample	191	72.0%	85 min	1.57%	C
SFO to PHL · Philadelphiathin sample	160	88.1%	172 min	0.62%	A+
SFO to OGG · Kahuluithin sample	154	95.4%	61 min	0.00%	A+
SFO to BOI · Boisethin sample	151	68.0%	94 min	0.66%	C+

Delay causes

What held SFO up in December

One category carries most of the weight here. Late-arriving aircraft accounts for 44% of the 226,000 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
44%
Carrier
31%
National Airspace System
18%
Extreme weather
7%
Security
0%

44% 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 226,000 reported delay minutes here, that single category outweighs weather by 6 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 225,721 reported delay minutes.

Cancellations sit at 1.07% against a national 1.55%, which is ordinary. Diversions add another 0.29%.

For anyone connecting, the number to weigh is not the on-time rate but the tail behind it. 9.9% of arrivals land a full hour or more behind schedule, against 10.0% nationally. A 45-minute layover does not survive that, and no amount of walking quickly changes it. Ninety minutes is the honest minimum here, and two hours if the onward flight is on a separate ticket.

What to do with this

Flying from SFO in December

For a December trip through SFO: expect 76.3% on time and 1.07% cancelled, going by December 2025. The 5am–8am window was the strongest part of the day.

San Francisco International (SFO), the whole year
SFO in July73.9%
SFO in August79.6%
SFO in September82.4%
SFO in October80.1%
SFO in November78.6%
SFO in January82.5%
SFO in February81.7%
SFO in March84.0%
SFO in April74.7%
SFO in May70.1%
SFO in June67.1%

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