The Met Office has moved to reveal why hayfever sufferers are suffering so badly this year as a 34C heatwave hits the UK.

The national weather agency has warned pollen levels are expected to skyrocket this week as temperatures soar.

The reason for such high levels could be the warm yet wet May we experienced this year which has contributed to particularly aggressive pollen grains.

The Met Office said rising temperatures on top of breezes across the UK has caused a “pollen bomb”.

Met Office Relationship Manager for Health and Air Quality, Yolanda Clewlow, spoke to the Weather Snap podcast to explain the reason behind such high pollen counts.

She said: “The grass pollen season usually follows quite a consistent pattern and there tends to be two peaks, one in the first half of June and then another one in early July. That’s because we have about 150 different species of grass and they all flower at different times over spring and summer, although only some of them are allergenic.

“In terms of the numbers of pollen grains in the air, what we’re seeing isn’t especially noteworthy compared to what we’ve had in previous years. However, the potency of these pollen grains could be more intense this year, and that comes down to the weather we’ve had in spring.”

Clewlow added: “A warm and wet May, coupled with a relatively warm spring, means there’s a chance that the pollen that has developed is particularly potent, even if the amounts aren’t dramatically different.”

Met Office tips to avoid hayfever

Speaking about ways to relieve symptoms, Yolanda added: “The best defence against symptoms is to avoid the stimulus.

“Avoiding the pollen that you have an allergy to can really help and the levels of pollen in the air can fluctuate dramatically through the day.

“What’s typical is that a gentle breeze will lift the pollen off the plants early in the morning, the warm air will then carry this up and it’ll be optimal for getting into our lungs in mid-to-late morning.

“Interestingly, by the very middle of the day the pollen will often be carried up very high in the atmosphere, which can make the pollen count much lower near the ground. And then you can get that extra burst of pollen again in the evening as the air cools and allows the pollen to settle.”