IT IS THE time of year when you might expect there to be snow in the air.

But instead people in Hampshire are being warned to brace themselves for Saharan dust to settle on the South, prompting health risks for hundreds of residents.

The Department for Environment, Food and Rural Affairs (Defra) has issued alerts for most of the country throughout today (Thurs, Dec 17).

The cloud of dust has been whipped up by strong winds over the desert in north Africa before it is sent up into the sky and transported in the upper part of the atmosphere.

The cloud has been transported north towards the UK at a high altitude and will mix with local pollutants when it hits the country.

It is not the first time Saharan dust has been deposited on Hampshire, with a health warning issued back in April after another cloud was blown towards the UK.

However it is unusual for it to happen in the winter, with it usually occurring during the spring.

For most people the only impact will be the thin layer of dust left on their cars and windows.

But Defra says that elderly people, asthma sufferers and people with breathing difficulties could face risks as a result of the dust, and people are being advised to avoid exercise if they notice problems.

A spokesman for Defra said: ''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.''

Charity Asthma UK is also warning that the cloud could create a "perfect storm" of conditions to affect asthma sufferers.

Andrew Proctor, the organisation's director of advice and support, said: ''People with asthma need to take extra care. We are facing a perfect storm of asthma triggers, with air pollution and weather changes increasing the risk of potentially fatal asthma attacks for millions of people with the condition.

''Two-thirds of people with asthma find that air pollution makes their asthma worse, and even more tell us that changes in the winter weather can trigger asthma attacks.

''If air pollution or cold weather makes your asthma worse, do check forecasts and carry your reliever inhaler with you at all times.''

It comes as bookmakers slashed the odds on this Christmas being the warmest on record.

Coral's odds have tumbled from 5/1 to 2/1 in recent days, with the chances of a white Christmas Day now a long show.

And a spokesman for John Hill said: "We have pushed the odds out to evens from 1/2 in light of the recent forecasts, however, we will be sweating on Christmas Day because if there is now snow in the UK, we will be forced to pay out our biggest liability to date on a white Christmas.''