Ground stop at Seattle-Tacoma (SEA), Oct 15, 2026

ActiveDense fog halts Seattle-Tacoma departures for about two hours

SEA airport page Replay the day

Started: Thu, Oct 15, 8:09 AM PDT15:09 UTC
Scheduled until: 9:30 am PDT
In effect for: 1 hr 17 min
Cause: low visibility

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

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What happened

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

Cause: Dense fog cut visibility to about an eighth of a mile, so planes could not safely land or take off at Sea-Tac.

The ground stop began at 15:09 UTC on October 15, 2026, and was still in effect about an hour later. Departures bound for Seattle-Tacoma were held, and the advisory lists 674 delayed flights. Air traffic control rates the chance of an extension as medium.

Impact by airline

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

Airline	On ground	Holding
Alaska Airlines AS	18	—
Delta Air Lines DL	10	—
Horizon Air QX	5	—
SkyWest Airlines OO	5	—
Southwest Airlines WN	3	—
Empire Airlines PN	2	—
United Airlines UA	2	—
American Airlines AA	1	—
Air Canada AC	1	—
Air Transport International 8C	1	—
Hainan Airlines HU	1	—
FedEx Express FX	1	—
Frontier Airlines F9	1	—
Singapore Airlines SQ	1	—

Impact by region

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

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

Aircraft at the airport

Peak 44 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 15, 8:09 AM PDT
Ground stop issued at SEA for low visibility, until 9:30 am PDT. Departures held from ZLC, ZOA, ZSE.

Advisories

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

ATCSCC ADVZY 045 SEA/ZSE 10/15/2026 CDM GROUND STOP

CTL ELEMENT: SEA
ELEMENT TYPE: APT
ADL TIME: 1506Z
GROUND STOP PERIOD: 15/1456Z - 15/1630Z
DEP FACILITIES INCLUDED: (1stTier+CZV_AP) ZLC ZOA ZSE  CYEG CYVR CYYC
 CYYJ CYLW
PREVIOUS TOTAL, MAXIMUM, AVERAGE DELAYS: 0 / 0 / 0
NEW TOTAL, MAXIMUM, AVERAGE DELAYS: 674 / 89 / 48
PROBABILITY OF EXTENSION: MEDIUM
IMPACTING CONDITION: WEATHER / LOW VISIBILITY
COMMENTS: LOW VIS. LOW CIG. FOG.

Original advisory ↗

Where flights were held

Departures to SEA were held from 3 centers (1stTier+CZV_AP).

Chance of extension: MEDIUM

Weather at the time

METAR, weather alerts and SIGMETs at the airport during the stop.

When it started

LIFR

METAR KSEA 151453Z 01008KT 1/8SM R16L/1600V4500FT FG VV001 11/11 A3039 RMK AO2 SFC VIS 1/2 SLP299 T01060106 50005 · observed Oct 15, 7:53 AM PDT

Dense Fog Advisory · Dense Fog Advisory issued October 15 at 2:07AM PDT until October 15 at 9:00AM PDT by NWS Seattle WA

Latest during the stop

LIFR

METAR KSEA 151553Z 02007KT 1/8SM R16L/4000VP6000FT FG VV001 11/10 A3040 RMK AO2 SFC VIS 3/4 SLP302 T01060100 · observed Oct 15, 8:53 AM PDT

Dense Fog Advisory · Dense Fog Advisory issued October 15 at 8:36AM PDT until October 15 at 10:00AM PDT by NWS Seattle WA

Seattle-Tacoma (SEA) live status →Every ground stop at SEA →Replay Oct 15, 2026 on the map →Read the full advisory ↗What is a ground stop? →

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 SEA 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 SEA, every 30 minutes while active and once more after the end. Delayed means 15 or more minutes late at SEA; 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 SEA 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 SEA, 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.