Is the flight to France turbulent?
Cruise is smooth most of the way, but flights to Paris and Nice cross the North Atlantic jet stream, which can cause clear-air turbulence — most likely in winter. Flights to Nice may add brief mountain-wave turbulence near the Alps on descent.
When is the smoothest time to fly to France?
May through September generally has a weaker, more northerly jet stream and the calmest transatlantic air. Winter (Nov–Mar) brings the strongest jet and the most clear-air turbulence.
Why is there turbulence over the Atlantic?
The North Atlantic jet stream — a fast river of air at cruise altitude — creates wind shear at its edges that can jolt an aircraft without warning (clear-air turbulence, or CAT). It is strongest in winter and on the eastbound US→Europe leg, which rides the jet. Pilots change altitude to find smoother air, but CAT is invisible on radar, so it is the main reason to keep your belt on.
Where should I sit on a flight to France?
Over the wing, near the aircraft's center of gravity, gives the steadiest ride. Keep your seatbelt fastened even when the sign is off — clear-air turbulence over the Atlantic can appear suddenly. On overnight flights the smoothest air is usually found by belting over the blanket and staying buckled while you sleep.