LONDON, Aug. 6 (Xinhua) -- The British tourism industry is hailing the current huge heatwave in the country as a windfall when visitors flock to London's outdoor attractions in record numbers.

The latest figures suggested that destinations such as Hampton Court, Greenwich Park and London Zoo have seen a rise in visitors of about six percent on last year so far.

Restaurants, bars and cafes with open-air terraces, such as Madison roof-top bar near St Paul's, have also been reported as "packed" with last week's customer numbers up by as much as 30 percent on last summer.

Last week, when there was almost constant sunshine, the group's revenues were 11 percent higher than in the same week last year.

The Heart of London Business Alliance which represents traders in the Leicester Square in the central area of the capital, on Monday said retail sales were up by 7 percent in June.

Across the West End as a whole they were up 1.7 percent, the first month of year-on-year growth since last October. It came after six months of declining visitor numbers.

British weather forecasters said the current hot spell will continue until Wednesday when cooler air from the Atlantic sweeps into Britain behind a cold front.

Britain could bake in the heatwave until the end of October, according to the latest long-range forecasts.