✈️ London (LHR) ⇄ Seattle (SEA): turbulence forecast

Checking whether your LHR–SEA flight will be bumpy? RideScore samples the live forecast winds at cruise altitude along the actual London–Seattle route and scores every leg of the flight, in plain English.

What makes this route bumpy (or not)

This is a jet-stream route: crossing the North Atlantic (or continental) jet means winter flights often pick up clear-air turbulence where wind speeds change sharply with altitude. Eastbound flights ride the tailwind; westbound flights fight it and are usually a little longer and, in winter, a little bumpier.

How the forecast works

RideScore reads the same global weather models professionals use (NOAA GFS / ECMWF via Open-Meteo), computes wind shear, jet-stream strength and storm energy at up to 11 points along the LHR–SEA great-circle, and turns it into a simple 0–10 bumpiness score for each leg of your flight — plus recent pilot reports from aircraft that just flew nearby. It's free, with no account and no tracking, and works up to 16 days ahead.

Common questions

Is the LHR to SEA flight usually turbulent?

It varies day to day with the winds aloft. This is a jet-stream route: crossing the North Atlantic (or continental) jet means winter flights often pick up clear-air turbulence where wind speeds change sharply with altitude. Eastbound flights ride the tailwind; westbound flights fight it and are usually a little longer and, in winter, a little bumpier. Check the live forecast on RideScore just before you fly — it samples the actual forecast winds along the London–Seattle route at cruise altitude.

How long is the flight from London to Seattle?

The great-circle distance is about 7,702 km (4,783 miles), which works out to roughly 9h 34m in the air depending on winds and routing.

Is turbulence on this route dangerous?

No — turbulence is uncomfortable, not dangerous to the aircraft. Modern jets are built for far worse than anything encountered in normal service, and pilots route around the roughest air. Keep your seatbelt fastened and it is a non-event.

More routes from London (LHR) · More routes from Seattle (SEA)

This page shows typical route characteristics; conditions on your day will differ — run the live forecast. Estimates only, not an aviation weather briefing. © 2026 RideScore · made with ❤️ in Amsterdam · About · Terms