The Shanghai government Wednesday extended the deadline for residents using free tickets to the World Expo for five days. This was because many residents had been put off attending earlier this month because of the intense heat.

The Expo organizer was worried about a huge influx of visitors in the last few days of the month as about 800,000 tickets due to expire then had still to be used.

If the deadline had been not extended, organizers feared the number of visitors would exceed 600,000 on Saturday, just about the maximum capacity of the site, said Zhang Qing, deputy director of Expo Operation Headquarters.

About 260,000 free tickets had not been used by the end of July, while about 100,000 were not used in June.

Last Saturday saw the largest number of visitors to date - 568,300.

The city's weather authorities said the city's weather in August had been "abnormal" with a record-setting 27 high-temperature days where the maximum temperature was over 35 degrees Celsius, including four days over 39 degrees.

However, the heat didn't deter tourists from visiting the city.

From January to July, the city received more than 4.6 million tourists, near 34 percent more than the same period last year, after the Expo gave the local tourist industry a major boost, the city's tourism authorities said yesterday.

Officials said nearly 60 percent of tourists who stayed overnight in the city visited the Expo. Tourists from Hong Kong, Macau, Taiwan, Japan and South Korea showed more interest in the Expo than tourists from other countries and regions, the Shanghai Tourism Administration said.

From May to August 20, the average room occupancy at local hotels was around 80 percent, about 30 percentage points higher than last year for the same period. Room prices were 27 to 34 percent higher than those of last year's peak season but officials said that the increases were acceptable.