The Olympic Flames: China rehearses spectacular Games firework display

The futuristic structure, dubbed the Bird's Nest because of its lattice-like design, will be the home of the Games from August 8.

Fireworks are set off during a rehearsal of the opening ceremony at the Bird Nest National Stadium in Beijing, China

But the best-laid plans can go wrong  - so this extravaganza of pyrotechnics was merely a rehearsal by the organisers for the opening ceremony in three weeks time.

Built at a cost of around £250million, and completed in March this year, the 1,000ft long stadium used 25 miles of steel in its construction and will seat up to 91,000 for the main track and field events as well as accommodating the opening and closing ceremonies.

Fireworks explode above the stadium

Fireworks are usually the one of the highlights of any Olympic opening ceremony - and if these ones were any barometer of the show China hopes to hold, it will be a good one.

That is, if it doesn't rain. Chinese state media says there is a 41 per cent chance of rain during the opening ceremony at next month's Olympic Games in Beijing.

Another secret slips out as performers pose for photos ahead of the rehearsal

But the China Daily newspaper says that according to historical data analysed by the China Meteorological Administration if it does rains it is likely to be light.

The director general of the opening ceremony, Chinese film director Zhang Yimou, has said rain is the top worry for the ceremony.

The China Daily today quotes Chen Zhenlin, director of the Olympic Weather Service center, as saying thunderstorms, heavy rain, high temperatures, muggy skies and hailstorms still pose a threat,

The paper says global warming has also caused more extreme weather.

The CMA says Beijing experienced its wettest June in 15 years.

Spectacular: Chinese performers in lavish costumes practice their routine