A yellow-orange haze smothered several regions in Greece after days of strong winds from the south, limiting visibility and prompting warnings from the authorities of breathing risks.

Skies over southern Greece turned an orange hue on Tuesday as clouds of dust blown across the Mediterranean Sea from North Africa covered Athens and other Greek cities, one of the worst such episodes to hit the country since 2018, officials said.

Strong southerly winds carried the dust from the Sahara Desert, giving the atmosphere of the Greek capital a Martian-like filter in the last hours of daylight. The yellow-orange haze limited visibility and prompted warnings from the authorities of breathing risks.

“It’s one of the most serious episodes of dust and sand concentrations from the Sahara since March 21-22, 2018, when the clouds invaded the island of Crete in particular,” said Kostas Lagouvardos, weather research director at the Athens Observatory.

Greece had already been struck in late March and early April by Sahara dust clouds that also smothered parts of Switzerland and southern France.

Authorities warned that the dust concentrations can reduce sunlight and visibility while increasing concentrations of fine pollution particles, posing risks for people with underlying health problems.

The Sahara releases 60 to 200m tonnes of mineral dust a year. While the largest particles come rapidly back down to earth, the smallest can travel thousands of kilometres, potentially reaching all of Europe.

The Greek weather service said the skies would begin to clear on Wednesday as winds shift and move the dust. 

On Tuesday, the daily high in parts of the southern island of Crete topped 30 degrees Celsius, more than 20 degrees higher than what was registered in much of northern Greece.

People took to social media to express surprise at the orange skies that covered the city.

The strong southerly winds over the past few days have also fanned unseasonal early wildfires in the country’s south.

The fire service said Tuesday evening that a total of 25 wildfires broke out across Greece in the past 24 hours. It added that three people were arrested on the Aegean Sea resort island of Paros on suspicion of accidentally starting a scrub blaze on Monday.

There were no significant damages or injuries reported, and the fire was quickly brought under control.

Another blaze that broke out on Crete near a naval base was also contained on Tuesday.

Greece suffers devastating and often deadly forest blazes every summer, and last year the country recorded the European Union's largest wildfire in more than two decades. 

Persistent drought combined with high spring temperatures has raised fears of a particularly challenging period for firefighters in the coming months.