The highly-addictive weather drama continued yesterday as the UK temperature rose to a six-year high of 33.5C in London while the public braced for violent "tropical" thunderstorms and flooding across the country.

In what amounts to an extreme weather watershed, the focus gave way last night from the threat of wildfires to heavy rain and floods.

"Heavy rainfall can create fast-flowing water that may look safe but can still be powerful enough to knock you off your feet. We want people to stay well away from any floodwater, streams and rivers and keep a close eye on their children and dogs to make sure they stay away from the way water," said Peter Cowup, London Fire Brigade's acting head of operational procedures.

Download the new Independent Premium app Sharing the full story, not just the headlines

Breaching 33C the first time since the heatwave began 18 days ago, the UK is in for heavy outbursts of rain across-the-board today, the Met Office warned. This is likely to result in widespread flooding because the historically low level of rain this month has left the ground extremely hard, the forecaster added.

Today marks a decisive end to a three week period of rainfall that was so low, Britain had been on course for the driest July since 1825 and firefighters had battled wildfires around the country.

"From Monday night and into Tuesday, some very violent weather could be kicking off, with thunderstorms across quite a lot of England, Scotland and Wales," warned senior Met Office forecaster Brendan Jones.

"We will see some quite lively storms and with the high temperatures it will be almost tropical in the way it feels," he added.

Scotland, east Midlands, the East of England, London and the South East, the North East and the South West will all be hit by heavy downpours, the Met Office predicted yesterday.

Mr Jones said the conditions would be "very, very humid" with warm air moving into Britain from Spain and France. The storms will be unleashed as that humid air clashes with an incoming cold air front, which will also push down the temperatures to the mid 20s on Wednesday, Thursday and Friday.

The Met Office site shows forecasts for humidity as high as 89 per cent in the home counties in the early hours of Wednesday - with a minimum temperature of 18C.

The long run of hot weather continued to impact on human, animal and inanimate behaviour in all sorts of ways yesterday.

The West Midland Safari Park in Bewdley, Worchestershire, reported its population of Meerkats had been having the time of their lives as they basked in the sun in recent days.

"The meerkats love nothing more than hot, sunny weather - after all their ancestors are native to the hot climes of southern Africa, therefore the exceptionally balmy days that they are currently experiencing at the park is rather like being back home," said park spokewoman Wendy Jackson.

Steam train enthusiasts were not so enthusiastic however, as fears of dry trackside vegetation catching fire from loco sparks forced a rail trip company to postpone two landmark journeys of a restored train hauled by the class A4 steam locomotive Bittern.