SUN-DRENCHED Britain was on course to break all weather records last night as bookmakers cut the odds on temperatures hitting the 100F mark.

William Hill is offering just 7/2 on the all-time high figure being recorded after a sweltering day which saw many parts of the country basking in temperatures eclipsing Florida and the Canary Islands.

Forecasters are tipping the weather to get even hotter with the possibility that temperatures could reach an all-time high of 37.2C (99F) tomorrow.

Britain has already seen the third warmest June and July for the past 100 years.

London was the hottest place in Britain yesterday with 32C (90F) - hotter than Barbados (31C/88F), where Prime Minister Tony Blair is enjoying a holiday with his family.

Daytrippers heading to Brighton, Blackpool and Bournemouth lapped up the bright sunshine with highs between 25C (77F) and 28C (82F).

And sun-seekers brought a welcome boost to the North Yorkshire coast, as countless deckchairs were pitched along the beaches of Scarborough and Whitby.

Steve Hollingworth, of Scarborough Borough Council's tourism department, said: "It's unbelievable. All of our attractions visitor numbers are up.

"Our visitors are all mainly from this region, with many booked in to stay three or four days after seeing the forecasts."

Further inland, at Flamingo Land, near Malton, zookeepers were taking drastic action to keep their prize exhibits happy in the heat.

Sean Drayton, of the theme park's zoo, said: "We have turned the heating off in the reptile house. They love the heat but this is just too warm for them."

In Leeds and Cardiff sun-worshippers soaked up temperatures as high as 27C (81F).

In Scotland, temperatures were forecast to nudge 30C (86F), with an outside chance of beating the record temperature set almost 100 years ago.

Southern parts of the country were also basking in sunshine, but most areas will have to wait until today to experience the best of the weather.

Jane Seddon, of the British Resorts Association, said: "The weather certainly makes a difference in England.

"If hot temperatures are promised for more than a week, people normally take the decision to go for an extended break."

However, the Department for Environment, Food and Rural Affairs warned that the heatwave conditions were causing summer smog, which could lead to health problems.

The smog effect is caused by an increased concentration of ozone at ground level, created by the reaction between sunlight and pollutants from car exhaust and other fuel emissions.

Train speed limits imposed amid rail buckling fears

Rail chiefs faced a backlash from passengers last night as rising temperatures forced them to impose speed restrictions on some of the country's busiest commuter lines.

As heat levels across the country soared, train operators were ordered to observe a 60mph speed limit because of the potential for derailments.

The West Coast Main Line and the cross country network were among the hardest hit by the restrictions, with some of the long-distance services halved to one an hour.

Network Rail's decision to introduce the precautionary speed limit followed concerns over track safety and the risk of sections buckling amid scorching temperatures.

Rail chiefs said that speed restrictions could remain in place until the end of the week.

Steve Hounsham, a spokesman for campaign group Transport 2000, said: "Obviously, safety comes first, but many people will be asking why our rail network can't cope with what is, after all, a relatively mild climate."

Peter Rayner, an expert in railway operations and safety, asked: "How has the railway network been able to get into the condition where such action is necessary?.

"That brings us back to the stewardship of Railtrack and probably their contractors who have, over the years, failed to put sufficient ballast down, which is an intrinsic part of this problem."

The restrictions will have the most damaging effect on long-distance Virgin services, with extended journey times between London and Birmingham, Manchester, Crewe and Scotland.

The disruption will also result in services between London and Birmingham reduced from half hourly to hourly, with a 60mph restriction imposed on routes across southern England.

Routes from London's Liverpool Street to Chelmsford and Norwich will also be affected.

Peter Henderson, Network Rail projects and engineering director, apologised in advance of any delays but said: "Our first priority is always to run a safe railway.

"With air temperatures expected at over 30 degrees in some areas today, we feel it is necessary and sensible to impose these speed restrictions.

"With temperatures dropping in the early evening, the restrictions are lifted. This obviously varies from location to location but tends to happen between 6pm and 8pm."