The sky has turned dark and the sun a deep orange because of Storm Ophelia.

All over England, the sky looked as if it was in the middle of a sandstorm. The sky was a deep brown and orange, and the sun turned red – or disappeared behind the swirls of sand in the sky.

If it resembled something you'd expect to see in the Sahara Desert, that's because it was. The sand and dust had been carried over from southern Europe and Africa by recent bizarre weather, and as it swirled around it turned the sky dark.

Red sun spotted in sky over UK Show all 6 1 /6 Red sun spotted in sky over UK Red sun spotted in sky over UK An orange sun in the sky at Builth Wells, Wales Alamy Live News. Red sun spotted in sky over UK A plane flies past the Shard in central London PA Red sun spotted in sky over UK Red sun spotted in the sky over Bromsgrove in Worcestershire PA Red sun spotted in sky over UK The sky turns an orange red in London Alamy Live News. Red sun spotted in sky over UK A Red Sun in the sky above Aberdovey on the Welsh Coast Jon Freeman/Alamy Live News Red sun spotted in sky over UK A red sun in the sky over North London Rex Features

As the sun moves through the dust, the light is reflected and refracted, meaning that even the light that was falling on the ground appeared to turn the colour of dirt.

The material is swirling high up in the atmosphere, meaning that it is safe to go outside and to breathe, and that the orange effect will pass fairly quickly.

The same thing has happened with the warm weather, which meant that those places that aren't being hit by the wet, stormy weather are actually seeing something like summer temperatures.

The unusual occurrence was seen in the South-west during the middle of Monday morning before spreading across the country in the afternoon.

A number of people shared photos and video online of the phenomenon. Sharon Derrick posted a video of the sun over Bristol and said: "Bristol looks like the film The Red Planet... the weather is bizarre."

Met Office forecaster Grahame Madge said the former hurricane is pulling air and dust up from southern Europe and Africa.

"It's all connected with Ophelia, on the eastern side of the low pressure system air is coming up in the southern direction," he said.

"Air is being pulled from southern Europe and Africa and that air contains a lot of dust.

"So it's most likely the appearance of sunset at midday is caused by the particles scattering the light and giving the appearance of a red sun.

Storm Ophelia's predicted path over Ireland and the UK

"It's certainly spectacular at the moment and quite a talking point, we've had a lot of calls about it."

Red sky at day: why is it happening?

Mr Madge told The Independent that the change in the sky was due to dust particles from the continent, being pulled up through a “vigorous and powerful system” connected to Storm Ophelia.

“It’s drawing air from the south that contains dust from the Sahara and is picking up smoke particles from the wildfires in Portugal and Spain. “These particles are helping to scatter the sunlight,” he said.

“So, just as we get at sunset, the particles in the atmosphere are scattering and diffusing the bluer wavelengths of sunlight, which is leaving more of the red light to come through.”

Debris from wildfires currently engulfing Portugal may also have been dragged up by the storm.

How long will it last?

As Storm Ophelia moves across Scotland on Tuesday and over the North Sea to Scandinavia, it will allow conditions in the south of Britain to “improve dramatically”, Mr Madge said, adding that the wind coming in from the Atlantic would not contain the same amount of dust.

It is expected to clear overnight.

Is it a rare phenomenon?

The UK encounters this phenomenon with Saharan dust about once or twice a year, Mr Madge said, though it usually happens overnight.

The addition of smoke particles from the wildfires may have added to the effect this time however, and people could wake up with a layer of dust on their cars in the morning.