Britons will be battered by “blood rain” this week as a Saharan dust plume is set to smother the UK. Dust from the Sahara Desert is set to fall to the Earth in showers from today. The strange phenomenon occurs when strong winds whip up sand and dust, and once airborne, they can be carried for thousands of miles. It is known as “blood rain” due to the dust’s reddish tint that can stain cars and windows. The Saharan plume could also leave an eerie hue in the sky. Met Office forecaster Marco Petagna said: “Saharan dust is being drawn north to affect the UK in the coming days, following recent dus…