What is blood rain? Met Office issues thunderstorm warning plus how Leeds will be affected by the weather forecast

A large cloud of Saharan dust is heading our way according to the Met Office, with a chance of red or orange rain in the UK as part of the phenomenon of 'blood rain'.

But why does blood rain occur, and how common is it?

Here is everything you need to know about blood rain, and if it will affect Leeds this weekend.

What is blood rain?

Blood rain is a red or orange-tinged rain that occurs when relatively high concentrations of red coloured dust get mixed into rain.

True blood rain, where the rain actually appears red, is relatively rare because you'd need red dust in fairly high concentrations - most cases of blood rain in the UK are barely noticeable.

How often does blood rain occur?

Cases of true blood rain are extremely rare across the world.

Each year on several occasions the UK will see rain falling with a small amount of dust mixed into it, usually from the Sahara, but it does not change the colour of the rain.

The dust from the Sahara is usually yellow or brown and mixed in very low concentrations, so the only time you may notice blood rain is after the fact when the dust coats things like cars and rooftops.

Why does blood rain happen?

Strong winds or storms can whip up dust and sand from the ground, lifting it into the air and sending it upwards into atmospheric circulation, where it can be carried for thousands of miles.

Eventually the dust will either fall out of the sky due to gravity or will be caught up in rain clouds, where it mixes with the water droplets.

When these fall as rain the raindrops could appear red.

When was the last case of true blood rain?

In 2001 in the southern Indian state of Kerala, monsoon rains flooded down with a red colour which was dark enough to stain people's clothing.

There were also reports of rains of other colours during the same monsoon season - including green and yellow rain.

What is the weather forecast looking like for Leeds this weekend?

Saturday

Mainly dry but often cloudy, although some bright or sunny spells will occur, along with a chance of an isolated afternoon shower.

Maximum temperature of 19C and minimum of 11C.

Sunday

Showers or longer spells of rain, these often heavy and also with a risk of thunder but Leeds likely to be one of the least affected areas.

Temperatures will be close to, or slightly below, 18C with a minimum of 10C.