Cars and pavements in the West Midlands have been found coated with a layer of dust from the Sahara desert.
Areas of Worcester, Stourbridge, Wolverhampton and Shropshire awoke to the phenomenon on Thursday.
It happens when strong winds carry the material into the atmosphere and then rain effectively washes it out of the sky, the Met Office says.
Saharan dust had also caused “picturesque” sunsets across the UK, the Met Office added.
Liz Bentley from the Royal Meteorological Society said: “We’ve seen the temperatures rise in the past few days and the reason for that is the air has come all the way from north Africa.
“In the last few days, instead of it going across the Atlantic to Brazil, it came north to us and the UK.”
Jim Dale, from the British Weather Service, said the event was common in hot weather.
“I don’t think we were too much expecting the showers to be honest with you,” Mr Dale said.