About 474,000 people braved the heat to visit the World Expo on Sunday, bringing the total number of visitors to the Shanghai event so far to more than 29 million.

The hot weather is expected to continue throughout this week with temperatures climbing above 35 degrees Celsius, according to the city's weather bureau.

Zhang Ruiyi, a chief service officer at the Shanghai Meteorological Bureau, said the duration and intensity of sunshine in the city would increase noticeably this week under the influence of a subtropical high.

The city would experience hot and sunny days for a period with the end of the plum rain season and maximum temperatures would range between 34 and 36 degrees.

Today is forecast to be sunny to cloudy with a low of 27 degrees and a high of 35. The forecast for tomorrow is sunny to cloudy with temperatures expected to hit 36 degrees.

Sunday a temperature of 35.2 degrees was recorded downtown.

The weather bureau issued a yellow heat alert, lowest of the three-level system, at 1:50 p.m. warning that temperatures would exceed 35 degrees.

The bureau said the yellow heat alert was issued earlier, at 1:35 p.m., at the Expo site to warn visitors of the danger of heatstroke and to encourage them to stay in the shade.

Many points at the Expo site recorded more than 36 degrees at around 2:00 p.m., but visitors were well prepared.

Many were seen with umbrellas, towels and fans to fight the heat. They also took refuge in air-conditioned places such as shops, the underground station of the Metro's Line 13, restaurants and medical stations.

"It is better than we have expected probably because we have prepared well," said Jerry Wang, a university student from Zhejiang Province. He escaped the heat by heading for the Metro station on the Expo site at around 1pm.