London to New York turbulence
The busiest long-haul route in the world crosses the North Atlantic jet stream every single time. Here is what that means for the ride, and the live forecast for your own departure.
Local time at the departure airport.
Where the bumps sit on this route
The great circle from Heathrow to Kennedy arcs north over Ireland, the open Atlantic and Newfoundland — and spends most of that time inside or beside the jet stream.
Live forecast along the actual great circle, shaded by the same four-level scale the app uses.
Why the North Atlantic is the bumpiest crossing there is
The jet stream is a ribbon of wind two hundred knots and faster, and over the North Atlantic it sits almost exactly where the tracks between Europe and the American northeast have to go. Flights west to New York usually fight it; flights east to London ride it, which is why the return is often an hour shorter. Either way the aircraft spends hours near the boundary between very fast air and much slower air, and that boundary is where smooth flow tears into eddies.
That is clear air turbulence — the kind with no cloud, nothing on the weather radar and no warning you could see out of the window. It is also the kind that is genuinely forecastable, because the wind shear that causes it shows up in the same global models every airline's dispatch office plans around.
The practical shape of a typical crossing: smooth climb out of London, a stretch of light-to-moderate air somewhere between Ireland and mid-ocean where the route crosses the jet core, and a generally calmer descent into New York. The rough part is usually measured in tens of minutes, not hours, and the crew will often ask for a different altitude rather than fly through the worst of it.
London to New York, season by season
- ✓November to March is reliably the roughest. The winter jet stream is faster, further south and more sharply curved, which puts more shear directly across the track.
- ✓Westbound is usually longer and often bumpier. Heading into the jet means more time inside it — a London to New York flight is typically 7h30m or more against an eastbound return near 6h30m.
- ✓The middle third is where it happens. Departure and arrival are normally the smooth parts; the rough air tends to arrive somewhere between two and four hours in.
- ✓Storms matter more in summer. Convection near the eastern seaboard can add bumps on descent into New York between June and September, which is a different mechanism from the jet stream entirely.
- ✓It is uncomfortable, not dangerous. No large modern airliner has been lost to turbulence, and the injuries that do happen on this route happen to people who were not wearing a belt.
London to New York turbulence questions
How bumpy is the London to New York flight?
Most crossings are smooth with one patch of light or moderate air where the route meets the jet stream, typically lasting ten to thirty minutes. Genuinely rough crossings happen, mostly in winter, and severe turbulence is rare enough that flights are planned to avoid it. Check the forecast above for your actual date — the answer changes day to day, which is the whole point of forecasting it.
Which is smoother, BA117 or a daytime flight?
Departure time matters less than the weather on the day. What time does change is the jet stream position you meet, which moves north and south over hours, so two flights on the same route six hours apart can get different rides. The forecaster above takes your departure time into account rather than averaging the day.
Is the return from New York to London smoother?
Often, yes — eastbound flights ride the jet stream rather than crossing its edge at an angle, so they can spend less time in the shear layer while still getting the tailwind. It is not a rule, and a strongly curved jet can make the eastbound leg the rougher one.
Which seat is smoothest on this route?
Over the wing, near the aircraft's centre of gravity, because that is the point it pivots around. The very back of the cabin moves most. This is true on any aircraft and any route, but it is worth knowing on a seven-hour one.
What aircraft flies London to New York?
Mostly widebodies — 777s, 787s, A350s and A330s, with the occasional A380. A heavier aircraft rides a given gust more smoothly than a light one, which is one reason long-haul routes tend to feel calmer than a short hop in a regional jet.
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