Ground stop at San Francisco (SFO), Oct 18, 2026

ActiveLow ceilings halt departures from San Francisco airport

Started: Sun, Oct 18, 8:04 PM PDT03:04 UTC
Scheduled until: 9:15 pm PDT
In effect for: 24 min
Cause: low ceilings

Live: this page updates every minute while the ground stop is in effect.

Flying to or from SFO? Is your flight affected?

Enter your flight number to see its EDCT, the ground stop or delay program at its destination, and its status.

What happened

AI-written · may contain mistakes. Written from the advisory text and weather only.

Cause: Clouds hung low over San Francisco, at about 1,200 and 1,600 feet, which is too low for planes to land safely, so departures were paused.

A ground stop at San Francisco began at 03:04 UTC on October 19, 2026, and was still in effect 16 minutes later. Departures were held from four air traffic control centers, and the stop is scheduled to end at 9:15 pm Pacific time. Air traffic control says an extension is medium probability, with 993 total delays reported so far.

Impact by airline

Aircraft seen on the ground at SFO and holding nearby, by airline.

Airline	On ground	Holding
United Airlines UA	6	—
American Airlines AA	4	—
Southwest Airlines WN	3	—
Alaska Airlines AS	2	—
JetBlue B6	2	—
SkyWest Airlines OO	2	—
Copa Airlines CM	1	—
EVA Air BR	1	—
Breeze Airways MX	1	—
Singapore Airlines SQ	1	—
Swiss LX	1	—

Impact by region

Air traffic control centers whose departures to the airport were held.

Center	Status
Los Angeles Center (ZLA)	Held
Salt Lake City Center (ZLC)	Held
Oakland Center (ZOA)	Held
Seattle Center (ZSE)	Held

Aircraft at the airport

Peak 25 on the ground, 0 holding nearby.

On the ground Holding nearby

Timeline

Every change published while the ground stop was in effect, as seen each minute.

Oct 18, 8:04 PM PDT
Ground stop issued at SFO for low, until 9:15 pm PDT. Departures held from ZLA, ZLC, ZOA, ZSE.
Oct 18, 8:06 PM PDT
Reason changed to low ceilings.

Advisories

The air traffic control advisories issued for this ground stop, as published.

ATCSCC ADVZY 010 SFO/ZOA 10/19/2026 CDM GROUND STOP

CTL ELEMENT: SFO
ELEMENT TYPE: APT
ADL TIME: 0300Z
GROUND STOP PERIOD: 19/0300Z - 19/0415Z
DEP FACILITIES INCLUDED: (1stTier) ZLA ZLC ZOA ZSE
PREVIOUS TOTAL, MAXIMUM, AVERAGE DELAYS: 0 / 0 / 0
NEW TOTAL, MAXIMUM, AVERAGE DELAYS: 993 / 71 / 38
PROBABILITY OF EXTENSION: MEDIUM
IMPACTING CONDITION: WEATHER / LOW CEILINGS
COMMENTS:

Original advisory ↗

How it is measured

Status, timeline, cause and held centers: the national airspace status feed, checked every minute, and the air traffic control advisories it links to.
Delays by airline and region: departures and arrivals at SFO 30 or more minutes late, by their estimated delay against the schedule, sampled every 10 minutes while the stop is active and once more after it ends.
Totals and cancellations: arrival and departure boards for SFO, every 30 minutes while active and once more after the end. Delayed means 15 or more minutes late at SFO; cancelled is the airline's cancelled status; codeshares count once. Flights scheduled from the start until an hour after the end are counted.
Held at origin: the same arrivals boards, which carry each flight's scheduled and actual departure from its origin. A flight is held when it is still scheduled, not departed, 15 or more minutes past its scheduled departure at a sample taken during the stop. In scope: its origin is in a held center or listed facility; flights from elsewhere are late for other reasons.
Inbound in the air: the same arrivals boards. At each board taken during the stop, a flight to SFO is in the air when it has departed (en route, or with an actual departure time) and not landed, cancelled or diverted; one still shown in the air over an hour past its arrival estimate, or departed more than 18 hours earlier, is treated as stale and left out.
Diversions: an inbound flight marked diverted during the stop or the wrap-up after it (not one marked before it could have departed), or one still shown in the air 30+ minutes past its arrival estimate that ADS-B (by its ICAO call sign) then found on the ground at another airport, not its origin. The diversion airport is the airport ADS-B found it at, else the updated destination. Cancellations never count. Regional flights flown under another call sign can't be found on ADS-B, so their diversion airport may be unknown.
Aircraft on the ground and holding: ADS-B positions around SFO, every 5 minutes; the airline is read from the call sign. Holding counts airline flights only (passenger, regional and cargo), not private, military or medical flights.
Weather: METARs, SIGMETs and weather alerts.
News: headline links filtered to this airport and these days; we show titles and links only.

Data sources are listed on the credits page.