Beijing, Shanghai, Zhejiang and Jiangsu in eastern China are experiencing an early summer with temperatures higher than usual for May, meteorologists told Xinhua Monday.

They said it was unknown if abnormal temperatures were a result of global warming.

Beijing recorded a high of 31.6 degrees Celsius on May 3, and has since seen its daily average temperature remain above 22 degrees Celsius for the following nine days. Daily average temperatures remaining above 22 degrees Celsius for five consecutive days indicates the advent of summer.

This is the earliest summer in Beijing since the city began to record detailed meteorological data 35 years ago.

Shanghai has also been hot and dry since the beginning of May. The eastern metropolis is experiencing the earliest summer in the past 136 years.

On Monday, Shanghai recorded a high of 35.3 degrees Celsius.

Also on Monday, eight out of 11 major cities in Zhejiang Province, including Hangzhou, Huzhou, Jiaxing, Shaoxing and Ningbo, each recorded a all-time high temperature of above 36 degrees Celsius, with the highest at 37.1 degrees Celsius in Huzhou.

Nanjing, Yangzhou, Zhenjiang, Wuxi, Changzhou and Taizhou recorded highs above 35 degrees Celsius Sunday.

Guo Hu, head of the Beijing Meteorological Bureau, attributed the high temperature to the sustained warm high air pressure and absence of cold air activities since the beginning of May.

He said that according to historical data, an early summer did not necessarily mean more days of extremely high temperatures for the whole summer.

(Xinhua News Agency May 11, 2009)