SHANGHAI, July 27, 2016 (Xinhua) --A nurse works at Children's Hospital of Fudan University in east China's Shanghai Municipality, July 27, 2016. Shanghai Meteorological Bureau issued this summer's second red alert for high temperature on Wednesday as about 40 degrees Celsius is expected in the Municipality. (Xinhua/Liu Ying)

SHANGHAI, July 27 (Xinhua) -- Shanghai issued its second red alert of the summer, due to a prolonged heatwave on Wednesday, with temperatures hitting their third highest since records began.

Temperatures reached 40.3 degrees Celsius as the heat wave entered its eighth day, according to the municipal meteorology station.

The sweltering weather is expected to continue until Aug. 2.

The meteorology station issued the first red alert on Sunday, with temperatures hitting 40 degrees Celsius.

China has a four-color-coded warning system for severe weather, with red being the most serious, followed by orange, yellow and blue.