Pollen “especially potent” caused by the recent hot and humid weather is causing worse-than-usual symptoms for those suffering from hay fever, the Met Office said.
The combination of humid and warm weather in May means that while the pollen count is not higher than usual, the pollen itself is stronger, according to experts.
Yolanda Clewlow, Met Office’s health and air quality relations manager, told the Met Office’s Weather Snap podcast: “The power of these pollen grains could be more intense this year. and that comes down to the weather we had in the spring.
“A warm, humid May, along with a relatively warm spring, means there is a possibility that the pollen that has developed may be especially powerful.”
Lawn pollen usually causes an increase in the symptoms of hay fever in early June and around the same time in July. This is because about 150 types of grass pollen bloom simultaneously.
Sky News weather producer Joanna Robinson said Saturday’s grass pollen count was “very high”.
Allergy UK also warned of a new phenomenon, electrical storm asthma, whereby people with asthma and hay fever suffer worse when the weather is turbulent.
During storms, more pollution and pollen are released into the air and people breathe in them, worsening the symptoms of both conditions.
The charity also said the pollen season starts earlier and lasts longer due to climate change.
Storm Alex, which hit the south coast of the United States earlier this week, could cause more worrying weather for the UK this weekend, but temperatures are expected to remain high.