Warning over high pollen and UV levels as temperatures set to hit 29C

Warnings have been issued over high levels of pollen and ultraviolet (UV) rays as the UK prepares for the warmest week of the year so far, the Met Office said.

Highs of 25C are likely on Monday and temperatures are expected to rise each day until a peak of 29C on Thursday, the Met Office said.

The conditions prompted the forecaster to warn people to take precautions when outside.

Met Office spokesman Oli Claydon said: “Two areas people should be aware of during this warm spell are high pollen and high UV.

“Obviously, hay fever sufferers should be aware of this as well.”

Prolonged exposure to UV rays, emitted by the sun, can lead to sunburn and an increased risk of skin cancer.

People can protect themselves by wearing at least factor 30 sunscreen, spending regular time in the shade and wearing suitable clothing, according to NHS guidance.

People who suffer from pollen allergies should try to keep the particles out of their eyes, face and hair by staying indoors if they can, or by wearing a mask and hat when outside, medical charity Allergy UK said.

They are also advised to shower and wash their hair regularly, and to remove the top layer of clothing when coming indoors.

The Met Office and London Fire Brigade have also urged caution around open water swimming after last month saw a 32% increase in water-related incidents compared with the same period last year, the LFB said.

Craig Carter, LFB assistant commissioner for prevention and protection, said: “Whether you’re walking by the river, spending time by canals or taking part in water-based activities, it’s important to be aware of the risks and take simple precautions to stay safe around London’s waterways.

“Even when the sun is shining, water temperatures can be dangerously cold. Cold water shock can affect anyone, no matter how fit or experienced they are.

“It can lead to water inhalation and, in the worst cases, drowning. Be particularly careful near the water’s edge, it’s easy to slip and fall unexpectedly.

“And think twice before jumping into open water.”

In the first quarter of 2025, LFB crews responded to 160 water-related incidents, averaging more than 13 per week compared with fewer than 11 a week in 2024, LFB said.

There may also be an increased risk of wildfires as the warm temperatures follow a spell of dry weather in April and March, Mr Claydon said.

So far in April, the UK has only recorded 51% of its average rainfall for this month, which Mr Claydon said is “well below average”.

Rain is expected later in the week, he added, with “some showers developing in the south of England through Thursday and into Friday”.

Temperature records for April and May are unlikely to be broken this week as the record for April stands at 29.4C, and May’s record is 32.8C, the Met Office said.

If temperatures reached 30C, it would be the earliest time of year for that figure to be recorded in the UK, with current record being May 12 in 1945, Mr Claydon said.