Pollution well being warning issued as Sahara Desert mud plume brings crimson skies on warmest day of the 12 months to date – with ‘blood rain’ forecast

Britain will be hit by a vast plume of Saharan dust over the coming hours – bringing fiery sunsets and even ‘blood rain’ as air pollution health alerts were activated.

Dust made up of sand and mineral particles from the desert in North Africa has been transported thousands of miles northwards towards the UK in recent days.

The plume will sweep across southern England, with the Government issuing a ‘very high’ pollution warning for parts of Kent, Essex, Suffolk and Norfolk tomorrow.

London and other parts of the South East were put on a ‘high’ alert – with particular concern for adults and children with heart or lung conditions, and older people.

Britons were also warned to watch out for ‘blood rain’, referring to downpours that take on a reddish tint once reaching the ground after mixing with Saharan dust.

This can leave a visible thin residue on vehicles and windows – with the Met Office advising motorists to wait until the end of the week if planning to wash their car.

It comes as temperatures hit 19.2C (66.6F) at Northolt in West London today, which made it the warmest day of 2026 so far – beating the 18.7C (65.6F) last Wednesday. 

BBC lead weather presenter Stav Danaos anticipates a ‘remarkable display’ in the sky, writing: ‘The striking colours appear high in the atmosphere, where the Saharan dust stays suspended for several kilometres before gradually drifting and settling.

‘These tiny particles scatter sunlight, filtering out the shorter blue and violet wavelengths and letting the longer red and orange tones shine through.

‘The effect transforms ordinary sunrises and sunsets into vivid displays, with glowing horizons and skies rich in gold, amber, and burnt orange, sometimes giving the landscape an almost surreal, otherworldly feel.’

The Department for Environment, Food & Rural Affairs (Defra) warned of ‘moderate air pollution levels possible for parts of England and Wales on Thursday, as a generally southerly flow brings some elevated Saharan dust north across the UK’.

For tomorrow, Defra said: ‘Moderate to perhaps locally some very high air pollution levels remain possible for the south and east of England on Friday.’

Officials also warned that the ‘risk of some moderate to perhaps locally high air pollution levels continues into the weekend and Monday as the generally southerly flow maintains a risk of elevated Saharan dust’.

In Defra’s advice for ‘high’ and ‘very high’ levels, it warns that short-term exposure to air pollution over hours or days can cause a range of health effects.

These include coughing; chest tightness and pain; difficulty breathing; eye, nose and throat irritation; worsening of asthma symptoms; worsening of heart-related symptoms, such as heart palpitations; and worsening of chronic obstructive pulmonary disease (COPD) symptoms.

People are advised to reduce their exposure to air pollution, especially if they are experiencing symptoms – and speak to their doctor or nurse if they have new symptoms; their symptoms get worse; or their symptoms do not get better after a week.

For adults and children with lung or heart conditions, and older people, Defra says: ‘You should adapt physically demanding activities outdoors, especially if your symptoms get worse.

‘Follow your agreed management plan if you have one – for example, an asthma action plan. Ask your doctor or nurse for a plan if you do not have one.’

Met Office spokeswoman Nicky Maxey told the Daily Mail today: ‘A plume of Saharan dust is being drawn northwards across Europe and into the UK.

‘The airborne dust is expected to continue moving across the UK through today and tomorrow. This can lead to hazier skies and, at times, deposits of dust on surfaces, such as cars, particularly if showers occur.

‘While Saharan dust itself is a natural particle, its presence in the atmosphere can contribute to higher overall particulate levels.

‘Light winds and more stable conditions, especially across southern and eastern parts of the UK, is limiting how quickly the dust disperses. This makes it easier for locally generated pollution to build up.’

The Met Office also issued an explanatory note on ‘blood rain’ yesterday, which it said is ‘refers to rain that takes on a reddish tint once it reaches the ground’.

It added: ‘The colour can vary from a faint rusty hue to deeper reds, depending on how much dust is present in the atmosphere at the time of rainfall.’

The weather service said rain can only appear red when relatively high concentrations of red‑coloured particles mix with the water droplets in the cloud.

When rainfall occurs while these particles – which are sand or dust rich in iron oxides – are suspended in the atmosphere, the droplets can take on the red tint.

The Met Office added that ‘genuinely red rain is extremely rare’ in practice, adding: ‘While dust‑laden rain is not uncommon in the UK, the concentration of particles is usually low, resulting in rain that looks normal to the naked eye.

‘Only after the rain dries might you notice a thin film of dust left on cars, windows, or outdoor surfaces.’

Forecasters also said the effects of dust‑laden rain this week may include ‘a light coating of dust on vehicles or windows’; ‘slightly reduced visibility at higher altitudes if the dust layer is particularly concentrated’ and ‘vivid sunrises or sunsets, as airborne dust can scatter sunlight and enhance colours’.

The Met Office added: ‘If you’re planning to wash your car, waiting until the end of the week may be wise, as additional dust pulses could reach the UK before conditions settle.’

Recent examples of visible ‘blood rain’ include in the early 2000s in Kerala, India, where rain containing unusually high concentrations of red particles stained clothes and surfaces.

Another in Burgos in Spain in 2022 saw people wake up to find cars covered in Saharan sand.

Speaking about today’s general forecast, Met Office meteorologist Honor Criswick said: ‘We have got a band of cloud and rain, this could be heavy at times, in western areas, it’s going to move its way eastwards.

‘To the east of that, it should be mostly fine. There should be lots of long sunny periods until that rain starts pushing into the east.’

It will be cloudier across much of England and Wales tomorrow, while Northern Ireland and Scotland will get more sunshine.

High temperatures of 11C (52F) to 12C (54F) are forecast across England and Wales tomorrow.

The weekend will be a mix of patchy cloud and some sunshine, with high temperatures of 12C to 13C (55F) on Saturday and 14C (57F) on Sunday.

‘It’s the first week of meteorological spring so not a bad forecast,’ Ms Criswick said.

Yesterday’s UK high was 17.8C (64.0F) at Porthmadog in North Wales, while the low was -5.5C (22.1F) at Altnaharra in Highlands.