Forecasters said this week that the UK may see “blood rain”as heavy thunderstorms hit parts of south-east England.
The thunderstorms were mixed with dust clouds, which created the possibility of red rainfall.
Dust clouds have caused strange weather effects in the UK before–yellow and orange skies over London are not an unfamiliar sight–but rain as red as blood may sound alarming.
So what exactly is blood rain, and will we really see any red rain this week?
What is blood rain?
Blood rain is a colloquial term to describe when the rain looks like it’s red. The Met Office says: “Blood rain is not actually a meteorological or scientific term–instead it’s a colloquial phrase which can be found going a fair way back in history.”
The rain can appear red when it gets mixed with high concentrations of red coloured dust.
Strong winds can pick up dust and sand, which can get caught up in atmospheric circulation and carried for thousands of miles.
The dust can then mix with the rain, causing the droplets to appear red when they fall.
Will we get blood rain in the UK?
Unfortunately, for anyone who was hoping to see a strange weather event, it is unlikely that the UK will see blood rain.
The Met Office has said that the levels of dust were low, and that the weather system has now moved away from the UK anyway.
Met Office Chief Meteorologist Paul Gundersen said: “Concentrations of dust in the recent system – which has now moved away from the UK – were relatively low so would have quickly been rained out and washed away.
“It’s not uncommon to have some dust particles mixed in with the rainfall when the source air comes from northern Africa. The most common impact of this can be a dusty film sometimes appearing on people’s cars.”
Has blood rain happened before?
Proper blood rain is rare–but it has happened.
In 2001, red rain poured over Kerala, India, and it was dark enough that it stained people’s clothes.
Although blood rain may sound alarming, there is a scientific explanation behind this event.
Scientists discovered that the red rain over Kerala was caused by airborne spores from terrestrial algae called Trentepohlia annulata.
