Expo visitors need not worry about Shanghai's constantly changing weather during the Shanghai World Expo. They will receive precise updated weather forecasts free on their mobile phones.

Construction began today on the pavilion of the United Nations' World Meteorological Organization in Pudong. The organization will build a hi-tech weather station inside the pavilion.

The station will update weather forecasts for all visitors every one to three hours. During the city's plum rain or typhoon seasons, the station will issue weather alerts and send updates every half an hour, said Xu Xiaofeng, deputy director of China Meteorological Administration and commissioner general of the organization's Expo exhibition.

People will also be able to get weather updates from a large screen in front of the pavilion or on the pavilion's Expo Website.

An artistic rendition of the MeteoWorld Pavilion. [en.expo2010.cn]

Expo 2010 will be held from May through October, the period includes Shanghai's plum rain, flood and typhoon seasons when people may encounter quickly changing weather.

The meteorological pavilion, will cover 2,000 square meters and will look like a huge white cloud with mist surrounding it. Visitors will be able to see a rainbow when the angle of the sunshine is below 42 degrees. The theme is "For Safety and Interest."

An artistic rendition of the MeteoWorld Pavilion. [en.expo2010.cn]

The pavilion will simulate climatic cataclysms.

The pavilion is expected to attract 40,000 people a day. It will be the first meteorological pavilion in the 157-year World Expo history.

WMO is the United Nation's authoritative voice on weather and the state of the environment. China is a member.