Only February and the hayfever season is already upon us, as sales of remedies rocket

Give me fever: Sufferers would not normally expect to be affected until at least late March

Sales of hayfever remedies have rocketed by 25 per cent over the past four weeks, when they would not normally begin to rise until late March.

Recent temperatures have been as much as 11C (21F) above normal – and last Tuesday they hit 18C (64F), making it the hottest February 12 on record.

The weather has forced scores of plants into early flower, including English hawthorn, which has started blooming eight weeks ahead of schedule.

Superdrug confirmed remedy sales have risen by a quarter over the past few weeks. And Boots has seen a 24 per cent rise – with sales of some particular brands nearly doubling.

Boots pharmacist Sarah Cameron said: "It's earlier than in previous years."

Allergy UK said its helpline was registering a much higher volume of calls.

Spokeswoman Muriel Simmons said: "Over the past three years we've noticed the season starting earlier but nothing like this year.

"If it's this bad now, then heaven help us in March.'

Met Office spokesman John Hammond said the winds at present were coming from the south and south-east, bringing more polluted air from industrial Europe.

He added: "There's a greater chance that this could be causing allergies to flare up. But spring is coming earlier and earlier every year."