When is the Seattle to London route most turbulent?

Check the monthly chart for exact patterns. Transatlantic and mountain routes are typically roughest in winter (Dec–Mar). Tropical routes peak during monsoon season.

SEA to LGW Turbulence Forecast

Q: Is the Seattle to London flight turbulent?

The SEA–LGW route typically experiences moderate turbulence.

Q: Which seat is smoothest on SEA to LGW?

Wing seats are smoothest. On a Boeing 757 · Airbus A330, that's rows 14–24. Avoid the rear of the aircraft.

Q: How long is the flight from SEA to LGW?

The SEA to LGW flight takes approximately 9h 45m, covering 4,811 miles at 37,000 feet.

Is the Seattle to London flight turbulent? Live forecast & historical patterns.

Live forecast

SEA

→

LGW

Seattle · London · 9h 45m

52.8

Turb Score

9h 45m

Duration

4,180 nm

Distance

37,000 ft

Cruise Alt.

Moderate

Typical

⚠️ Moderate turbulence today

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Typical turbulence along the route

Historical average pattern for SEA–LGW

0h1h2h3h4h5h6h9h 45m

Smooth

Light

Moderate

Heavy

About the SEA–LGW route

The Seattle to London route crosses the North Atlantic, where the jet stream is the primary source of turbulence. Flying at 37,000 feet, the aircraft encounters the strongest bumps roughly 2–5 hours into the flight. This is clear-air turbulence — no clouds, no visual warning — which makes a pre-flight forecast especially valuable.

The route is served by American Airlines, United, Delta on Boeing 757 · Airbus A330 aircraft, with flights typically cruising at 37,000 feet over a distance of 4,811 miles (4,180 nautical miles).

💡 Tip: Turbulence peaks mid-flight over the Atlantic. First and last hour are usually smooth.

Seattle to London Flight Time

How long is the flight from SEA to LGW?

9h 45m

Flight Time

4,811 mi

Distance

37,000 ft

Cruising Altitude

Boeing 757

Aircraft

The Seattle (SEA) to London (LGW) flight takes approximately 9h 45m, covering 4,811 miles (4,180 nautical miles) at 37,000 feet. The route is operated by American Airlines, United, Delta. Return flights (LGW to SEA) take a similar time, though westbound transatlantic and transpacific routes are typically 30–60 minutes longer due to headwinds.

Turbulence levels on SEA–LGW

What to expect at each phase of the flight

SmoothDeparture & arrival — climb and descent phases are generally calm

LightMinor bumps — drink stays in your cup, walking feels slightly unsteady

ModerateNoticeable bumps — stay seated with seatbelt on, service may pause

HeavyStrong jolts — unsecured items move, crew seated. Rare but possible

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Best time to fly SEA–LGW

Turbulence by month

Smooth

Light

Moderate

Rough

Best seat on SEA–LGW

Boeing 757

Front

Rows 1–13

Light

✓ Wing

Rows 14–24

Smoothest

Rear

Rows 25+

Rougher

Wing seats are over the center of gravity — least affected by turbulence.

What you'll see in the app

Full forecast, live map & seat recommendations

Similar routes

Other popular routes with turbulence data

SEA → LAX

Seattle → Los Angeles

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Is Turbulence Dangerous?

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Passenger Reports

The over the Atlantic section was legitimately rough. I was holding on to the armrests. Lasted maybe 40 minutes. One of the flight attendants had to sit down. Not a fun 9h 45m flight but we landed fine.

Solo traveler · May

Flew this in July expecting smooth skies based on past experience, but it was noticeably bumpier than usual. About an hour of moderate chop. Seatbelt sign basically stayed on.

Regular traveler · July

Rough patch mid-Atlantic in March — drinks went everywhere on the row behind me. Probably 45 minutes of actual turbulence. Nothing dangerous but definitely uncomfortable.

Business traveler · March

All SEA routes→ All LGW routes→

Frequently asked questions

Is the Seattle to London flight turbulent?

The SEA–LGW route typically experiences moderate turbulence. The turbulence score for this route is 52.8/100.

When is turbulence worst on SEA to LGW?

Turbulence peaks mid-flight over the Atlantic. First and last hour are usually smooth. Check the turbulence chart above for the typical pattern along this specific route.

Which seat is smoothest on SEA to LGW?

Wing seats are always the smoothest. On a Boeing 757 (the most common aircraft on this route), that's rows 14–24. Avoid the very rear of the aircraft — it amplifies turbulence motion.

How long is the flight from SEA to LGW?

The SEA to LGW flight takes approximately 9h 45m, covering 4,811 miles (4,180 nautical miles).

Which airlines fly SEA to LGW?

The main airlines operating this route are American Airlines, United, Delta, flying Boeing 757 · Airbus A330 aircraft.

Data Sources

PIREP — Pilot reports (PIREPs) submitted via FAA/ICAO systems, aggregated over 12+ months of historical data
SIGMET / AIRMET — Significant Meteorological Information bulletins from NOAA Aviation Weather Center
EDR data — Eddy Dissipation Rate measurements from commercial aircraft (ADS-B derived turbulence intensity)
Seasonal patterns — 5-year rolling averages of turbulence frequency and intensity by month for this route

Scores represent typical conditions. Actual turbulence varies daily. For real-time forecasts, use the Turbulence Forecast app. · About our data