Temperatures are forecast to rise steadily through the coming days with highs of around 17C possible in London by Sunday. It comes after a beast from the east cold snap brought the lowest temperatures for 25 years to parts of the country in the run up to mid-February. The switch from extreme cold to early spring-like conditions will spur alder, hazel, elm and willow to spew clouds of allergens into the air, experts warn.
It means allergy sufferers will be reaching for tissues and nasal sprays weeks earlier than usual.
Airborne allergens expert Max Wiseberg said: “If we get weather that’s warmer than normal for the time of year this could create a mini pollen bomb with flurries of alder, hazel, elm and willow pollen exploding into the air.
“This would make a very early start to the hay fever season, so sufferers should ensure they’re adequately prepared.”
Much of the UK will enjoy temperatures more usual for the start of spring rather than winter thanks to a blast from the Atlantic, the Met Office said.
Warmer weather could trigger fungal levels to rise along with tree pollen, according to the University of Worcester and the National Pollen Monitoring Network.
A university spokesman said: “Hazel and alder tree pollen are airborne, but the general risk will remain low, due to cold temperatures, until the weekend, when we could see the risk rise to moderate in southern and central regions.
“Penicillium [fungal spores] will be at a low to moderate risk during the cold weather this week, increasing at the weekend in milder conditions.”
Mr Wiseberg, creator of HayMax barrier balm, said: “New research from the US has found that the pollen season is now on average 20 days longer than it was three decades ago.
“As with many allergies, prevention can be better than cure. If pollen doesn’t get into your system, it can’t cause a reaction.
“Use an organic, drug free allergen barrier balm which is applied to the nostrils and bones of the eyes in the morning and throughout the day.”