Will a Saharan dust cloud hit Britain today?

A Saharan dust cloud is expected to settle over parts of Britain today.

Health warnings have been issued about reduced air quality with the elderly and asthma sufferers deemed most at risk.

The Department for Environment, Food and Rural Affairs (Defra) said high levels of pollution were expected over southern and central England, with Lincolnshire bearing the brunt.

It added elsewhere would experience moderate levels across parts of England and Wales although "large uncertainties remain with the timing and amount of dust".

The Met Office said the mild southerly airflow currently affecting the UK, leading to the fourth mildest start to December since 1960, has increased the chance of seeing some of the dust.

Forecasters said the mercury could rise as high as 17C in parts of south-east England.

Saharan dust is lifted from its source in west Africa by strong winds and is blown northwards in weather systems heading towards the UK.

From there, it can be transported worldwide by winds, covering distances of thousands of miles before getting caught in rain droplets in clouds, falling to the ground in rain.

When the water evaporates, a thin layer of dust is left on surfaces, such as cars.

Dr Sotiris Vardoulakis, head of Public Health England's Environmental Change Department, said: "While most people will not be affected by short term peaks in ambient air pollution, some individuals, such as those with existing heart or lung conditions, may experience increased symptoms.

"On occasions where levels are high, adults and children with lung problems, and adults with heart problems, should reduce strenuous physical exertion, particularly outdoors, and particularly if they experience symptoms.

"People with asthma may find they need to use their reliever inhaler more often. Older people should also reduce physical exertion.

"Anyone experiencing discomfort such as sore eyes, cough or sore throat should consider reducing activity, particularly outdoors."