Changzhou is battered by heavy rain today � the day the annual plum rain season begins.

Warm and humid weather with intermittent rains are the pattern for the next few days, said forecasters.

Announcing the official start of the rainy season, the Changzhou Meteorological Bureau said this was three days later than average. A subtropical high is moving toward the lower stream of Yangtze River and will bring frequent rainfall to the city throughout the week.

Plum rain season �mei yu jiin Chinese � is defined as starting on the first day of a five-day period when it rains on four days out of the five. This must be preceded by three out of five days when average temperatures exceeded 22 degrees Celsius. It usually begins on June 17 and lasts until early or mid-July.

The season � called so because it always occurs when the plums ripen � is characterized by extreme dampness and high temperatures. It lasts about 23 days on average in the city.

Forecasters say this year’s rain season will be shorter and less intense than last year.