Guangzhou, Guangdong province, is experiencing the longest summer in decades, as defined by the provincial Meteorological Service, which traditionally pegs the change of seasons to temperatures, not to the Earth's position relative to the sun.

By that measure, the city has yet to enter autumn as of Wednesday because it's still scorching hot these days, the service said in a statement.

As of Wednesday, Guangzhou had broken a three-decade heat record, having experienced 235 summer days as measured by temperature. The city experienced a total of 234 hot days in 1994, it said.

Guangzhou, which entered its warm temperature period on March 23, usually starts cooling around Nov 9. Based on current temperatures, the province still does not have autumn conditions, and so summer this year will continue, meteorologists said.

Meanwhile, at least four typhoons continue to threaten the southern metropolis, after the formation of typhoon Usagi — the 25th to aim at the Chinese coast. The others are Yinxing, Man-yi and Toraji, coming from the South China Sea on Tuesday, the statement said.

In addition to Yinxing, which had weakened, Typhoon Toraji, the 24th this year, is expected to affect Guangdong.

The general weather over land in Guangdong is expected to be stable, though it will be affected by the typhoons. Strong winds over water offshore are expected to be prolonged over the coming days, the statement said.