A COLD front is expected to arrive on Wednesday and bring the temperature down to the mid 20s along with some rain and strong winds, the Shanghai Meteorological Bureau said yesterday.

Today and tomorrow will be cloudy to overcast with the mercury ranging between 25 and 31 degrees Celsius, the bureau said.

A thundershower is possible tomorrow, it said.

Yesterday also marked the autumnal equinox.

The temperature will drop to between 20 and 24 degrees on Wednesday and forecasters said to expect more rain.

Temperatures will range between 18 and 25 degrees on Thursday and Friday, with more showers.

Wu Rui, a chief service officer at the bureau, told Shanghai Daily it is still too early for the start of autumn.

The bureau declares the start of autumn after the average temperature remains below 22 degrees for five consecutive days. The first of those five days is then considered the first day of autumn.

Between 1981 and 2010, the average start to autumn has been on October 2.

“There is very little chance autumn will begin before the end of September,” said Wu.