Fasten your seatbelt: The most turbulent European flight routes revealed

It seems we heard more about turbulence in 2024 than ever before.

Multiple reports of injuries on turbulent flights hit the headlines, including one Singapore Airlines flight where a passenger sadly died. This was the first time a person had been killed on a flight due to turbulence since 1997.

Data from the US Federal Aviation Administration (FAA) suggests that from 2009 to 2023, 37 passengers and 146 crew members were seriously injured due to turbulenceand it remains the single biggest cause of injuries on a commercial flight.

Turbulence can happen anywhere, but certain characteristics can make it more prevalent. So where in Europe are the most turbulent routes, and how do they compare with the rest of the world?

Europe’s most turbulent flight routes

New research from turbulence tracking website Turbli has highlighted which routes in Europe are the most likely to experience bumps. Eight of the top 10 most turbulent routes begin or end in Switzerland, with other routes passing over or around the Alps.

To quantify the likelihood of turbulence, Turbli uses eddy dissipation rate (EDR). This is a measurement of atmospheric turbulence that’s independent of the aircraft’s characteristics. It’s the standard metric for aviation turbulence used by the International Civil Aviation Organization (ICAO) and the World Meteorological Organization (WMO).

In full, the most turbulent routes in Europe in 2024 were:

Nice – Geneva: EDR 16.07
Nice – Zurich: 15.49
Milan – Zurich: 15.41
Milan – Lyon: 15.37
Nice – Basel: 15.33
Geneva – Zurich: 15.05
Nice – Lyon: 14.99
Geneva – Venice: 14.78
Lyon – Zurich: 14.74
Venice – Zurich: 14.67

According to Turbli, anything under an EDR of 20 is considered ‘light,’ with those between 20 and 40 being moderate. No routes in the world ranked as strong (40-60) or extreme (80-100) on a yearly average basis, although some individual incidents may well have crossed these thresholds.

Nevertheless, extreme turbulence is uncommon in Europe, so even these most turbulent routes are unlikely to see some of the devastating incidents of recent months.

In comparison, the most turbulent routes in the world were all in South Americacrisscrossing the Andes mountain range. The most turbulent route, with an EDR of 24.68, was Mendoza to Santiago, with Cordoba to Santiago in second, and Mendoza to Salta in third.

Why is turbulence more common near mountains?

In general, flying over or near mountains can cause turbulence, largely due to the way the wind interacts with the terrain.

When winds hit a mountainous areathey can be forced to rise upwards over the peaks, causing updraughts. These upwardly mobile currents may then hit a stable air barrier at altitude, forcing them back towards the ground again and creating a downdraught.

High peaks can also create something known as ‘mountain waves,’ caused by disturbance to horizontal airflow. These oscillations on the downwind side of high ground can cause vertical currents as strong as 2,000 ft/min, making the skies above rather bumpy.

These disruptions in air currents can effectively disrupt an aircraft’s flight pathcausing the plane to rise, drop, or bounce up and down as it passes through.

Also playing a part in the severity of turbulence is temperature and humidity. The warmer and more humid the air, the more extreme the turbulence will be, explaining why routes over the Andes tend to be worse.

Should you be worried about turbulence and is climate change making it worse?

Modern aircraft are designed to handle even the most extreme turbulence events without becoming damaged. The same cannot be said for passengers, however.

In all the turbulence events we saw in 2024, passengers who were safely strapped into their seats were able to walk away from the aircraft unscathed. It was the passengers and crew members who were not secured who suffered the most serious injuries.

Experts agree that turbulence is getting worse as a result of climate change. Specifically, the greater extremes in temperature and stronger, more unpredictable storms mean extreme turbulence events are likely to become more common. The University of Reading in the UK projects that by 2050 turbulence events will be twice as common.

The aviation industry is working hard to keep passengers safe. The International Air Transport Association (IATA) launched its Turbulence Aware Platform in 2018 and now has over 25 airlines contributing and consuming data through more than 2,600 aircraft. Data from the platform is used in cockpit instruments and flight planning software to better predict and avoid turbulence.

As well as data like this, pilots rely on sophisticated weather radar systems onboard aircraft to detect and avoid areas of turbulence. They also report in real-time to each other if turbulence is encountered on a route.

As much as airlines and aviation bodies are playing their part to help flights avoid turbulence, it can still be incredibly difficult to identify and avoid turbulent air. In particular, clear air turbulence, which has no visual clues to its presence, is almost impossible to identify and avoid.

According to the National Transportation Safety Bureau (NTSB) in 28 per cent of turbulence-related incidents, the flight crew received no warning that they were about to hit trouble.

As such, the advice for passengers concerned about turbulence is to always keep their seatbelt securely fastened when on an aircraft.