Tonight:
9°c
South swelters as North warned of floods
Ben Bailey02.07.09
London was set to swelter in the hottest temperatures of the year so far today.
Forecasters warned that the mercury was set to top 33C in the capital as the heatwave reached its climax.
But allergy sufferers were warned to brace themselves for the worst summer on record because of high pollen counts caused by the high temperatures.
Elsewhere in Britain, the hottest week in years was threatening to become a wash-out as parts of the country were put on flood alert.
As temperatures soared beyond 30C (86F) in parts of Surrey, the north east of England was hit by a torrential thunderstorm.
The Environment Agency warned south Wales and south west England were set to be hit by flash floods this morning.
Tony Conran, forecaster for MeteoGroup UK, the weather arm of the Press Association, said: "There remains a possibility for the hottest day of the year but for other parts there could be floods.
"There's an area of very heavy rain moving in towards the hills of Bodmin and Exmoor. Anywhere in Cornwall, Devon and Somerset there could be a hell of a lot of rain."
An Environment Agency spokesman added: "The Environment Agency and Met Office are warning homeowners, businesses and drivers in south west England and South Wales that heavy, thundery rain could lead to flash flooding, particularly from surface water drains and small watercourses."
Forecasters had previously raised the heatwave warning alert level from two to three.
The current weather spell is the hottest since July 2006, with yesterday the hottest of the year so far at 31.8C (89.2F).
The heatwave plan alert is in four stages, with green level one signalling "summer preparedness and long-term planning".
Level two is amber and signals "alert and readiness", while three is red for "heatwave action".
Level four is classed as "red emergency". Wayne Elliott, head of health forecasting at the Met Office, said: "There are four key things to try and remember during a heatwave.
"If possible stay out of the heat during the middle part of the day, cool yourself down, keep your environment cool and look out for others, especially older people, those living alone, babies and young children."
Yvonne Doyle, the Government's regional director of public health in the South East, said: "Everyone's health can be affected by the heat, with greater risks of dehydration, sunburn, heat exhaustion and heatstroke.
"Those most at risk are the very young and the very old, and people who already have health conditions, especially heart and respiratory problems - the heat can make their symptoms worse."
The London Ambulance Service said it had seen a busy few days and urged people to only call for an ambulance in a genuine emergency.
It has been treating large numbers of patients for breathing problems, chest pains, loss of consciousness and fainting.
As most parts of Britain basked in sunshine, the north east of England was hit by a torrential thunderstorm.
Police closed the A68 in both directions after a storm hit the Rowley Bridge area near Consett, County Durham, causing part of the bridge to collapse.
Debris fell on to a house undergoing renovation, trapping one workman inside the building for a short time.
