How turbulent is SIN-LHR typically?

Smooth cruise punctuated by brief bumps near thunderstorm cells, more likely in the afternoon.

What is the best altitude to avoid turbulence on SIN-LHR?

Lateral deviation around cells is the main tool. Where a climb helps, FL380-FL400 clears most of the smaller build-ups.

When is the best time of year to fly SIN-LHR?

The dry season for the region, and early morning departures year round.

What causes the turbulence on this route?

Tropical thunderstorm cells and the rising air columns around them.

Turbulence forecast SIN → LHR. Singapore to London Heathrow. SkyBriefing.

Singapore to London: what the SIN to LHR corridor looks like

Departure: Singapore Changi Airport, Singapore, Singapore
Arrival: London Heathrow Airport, London, the United Kingdom
Great-circle distance: 10,881 km (5,875 nm)
Typical airborne time: 13h 09m
Usual cruise levels: FL320 to FL410
Initial track: northwest bound

Route overview

Singapore Changi Airport (SIN) in Singapore, Singapore, to London Heathrow Airport (LHR) in London, the United Kingdom, is a great-circle distance of 10,881 km, about 5,875 nautical miles. At typical jet cruise speeds, and with an allowance for climb, descent and approach, that works out to roughly 13h 09m of airborne time. The great-circle track leaves Singapore northwest bound and spends most of the flight in subtropical air.

Leaving Singapore

Singapore Changi sits on the equator at sea level. Convective cloud is possible on any day of the year, so the climb out is planned with radar deviations in mind rather than around a season. The great-circle track leaves SIN northwest bound, and the first waypoint band of the flight sits close to 13.9N 77.9E. On a sector of 13h 09m, the climb to cruise takes roughly the first twenty to twenty five minutes.

Tropical convection along the route

Along the way the track passes over high latitude airspace where the polar jet stream lives. The midpoint of the SIN to LHR track lies near 26.4N 51.8E, about 5,441 km from Singapore, which is where the corridor spends its longest continuous stretch at cruise level. The corridor runs through warm, moist tropical air where convective cloud builds during the day. Those cells are radar visible, so lateral deviations of a few miles are the normal tool. Cruise between the cells is typically smooth, and the bumpy sections are short.

Cruise altitudes on this sector

Ultra long sectors begin cruise lower, often near FL320 because of the fuel load, and finish two or three step climbs higher, up to FL400 or FL410. Choice of level matters because turbulence is layered: a change of two or three thousand feet often puts the aircraft into calmer air, and that is one of the first adjustments a crew will request.

Arriving into London

Approaches into Heathrow are flown along the Thames valley, often after a hold. In an active westerly the last minutes are gusty, which is routine at this airport and something crews plan a speed margin for. Descent normally begins around 38.9N 25.7E, roughly 2,720 km before LHR, and takes about half an hour from cruise level to touchdown.

Seasonal pattern

The regional wet season brings more convective cloud along this track. In the dry season, and on early morning departures year round, the cruise is usually settled.

Flying this route with less worry

Turbulence on this corridor is a comfort issue rather than a safety one. Airliners are certified to handle loads well beyond anything the atmosphere produces here, crews are trained for it, and the seat belt sign is the tool that keeps the cabin settled. What this page adds is knowing in advance: the map and Calmness Score above use current WAFS forecast data for SIN to LHR, so you can see what to expect before you board.