BEIJING — China's national observatory issued a yellow alert for high temperatures on June 29, as heat waves swept vast regions of the country.

During daylight hours on June 29, temperatures in parts of Shanxi, Shaanxi, Gansu, Sichuan, Chongqing, Henan, Anhui, Hubei, Hunan, Jiangxi, Zhejiang, Fujian, Guangdong, Hainan, Xinjiang and Inner Mongolia are expected to hit 35 to 36 degrees Celsius, the National Meteorological Center said.

According to the forecast, temperatures in some of these regions will reach 39 degrees Celsius, or even exceed 40 degrees Celsius.

The meteorological center advised avoiding outdoor activities during high-temperature periods in the afternoon and suggested that workers exposed to high temperatures take necessary protective measures.

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