Route turbulence forecast
Seoul → Seattle
Turbulence forecast for flights from Incheon International Airport (ICN) to Seattle Tacoma International Airport (SEA).
Check flights on this route
Get a segment-by-segment turbulence forecast for any scheduled flight from ICN to SEA, with live wind and pilot reports.
Live status with real-time delays and cancellations.
What to expect on this route
Northbound · Great-circle bearing 41°
The route crosses mid-latitudes where the polar jet can influence flight conditions, though exposure is shorter than on genuine long-haul crossings. The route crosses or passes near the Rocky Mountains, which can generate mountain-wave turbulence downwind when upper-level winds are strong.
- Mountain crossings
- Rocky Mountains
- Ocean / water segments
- North Pacific
Seasonal turbulence pattern
This corridor is most turbulent in the northern winter (Nov–Mar), when the jet stream is strongest and sits closer to the route. Wind flowing over the Rocky Mountains can generate mountain-wave turbulence that extends hundreds of kilometres downwind — most pronounced in the northern winter (Nov–Mar), when upper-level winds are strongest.
- Peak turbulence
- November–March (Northern Hemisphere winter)
- Typically calmest
- Late spring to early autumn (May–September)
ICN → SEA turbulence FAQ
Is the Seoul to Seattle flight usually bumpy?
Most of the 8,373 km route sits in the subpolar band with moderate jet-stream exposure. Historically that means occasional clear-air turbulence at cruise altitude is normal, especially in winter. Mountain-wave effects near the Rocky Mountains add short bumpy stretches when upper-level winds are strong.
When is the best time to fly ICN to SEA for a smooth flight?
Statistically, Late spring to early autumn (May–September) sees the calmest conditions for this corridor. Within any season, morning departures see less convective (thunderstorm-driven) turbulence than afternoon flights.
How long is the flight from ICN to SEA?
Block time is usually around 10h 14m direct, cruising at approximately FL390 (39,000 ft). Actual duration varies with winds — tailwinds can shave 15–30 minutes, headwinds can add 30+ minutes on this northbound sector.
How accurate is Turbcast's forecast for this route?
We use live NOAA Aviation Weather Center pilot reports (PIREPs), SIGMETs and AIRMETs, layered with physics-based Ellrod and Richardson-number calculations from Open-Meteo pressure-level wind and temperature data. If a source is unavailable for a waypoint we show an em dash rather than invent a value.
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