But what has caused this layer of muck to be deposited on car bonnets, roofs and windscreens?
The answer could well lie thousands of miles away in Africa.
The strange scenario is one that has played out a number of times before across the UK and is usually put down to an unusual phenomenon which sees sand in the Sahara Desert get sucked up into the atmosphere by huge storms.
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This sand then travels for thousands of miles high up in the atmosphere before it is deposited in rain.
Over the last week much of the UK has seen temperatures soaring due to hot air funneling in from the southern Mediterranean and North Africa.
However, for many the heatwave came to an abrupt end last night with heavy downpours bringing with them the Saharan sand.
The Sahara Desert is the world’s largest hot desert spanning a number of African countries including Algeria, Egypt, Libya, Morocco and Sudan.