Tourists visit the West Lake scenic area in Hangzhou, capital of East China's Zhejiang Province on April 12, 2023. The city experienced sand and dust storm on April 12, according to the authorities. Photo: VCG

China's National Meteorological Center issued a new blue alert for sandstorms in multiple regions from north to south on Wednesday, with locations including Shanghai and East China's Jiangsu and Zhejiang provinces issuing weather pollution alerts from Tuesday night, reminding people to stay alert and limit high-intensity outdoor activity as the dust started to move south.

Affected by cold fronts and heavy winds, floating sand and dust will sweep across areas including North China's Beijing, the Inner Mongolia Autonomous Region and Hebei Province, Central China's Henan and Hubei provinces, as well as East China's Shanghai and Jiangsu and Zhejiang provinces, according to China's national observatory.

The latest round of sandstorms buffeting North China had covered 2.29 million square kilometers and affected at least 15 provincial-level regions and 409 million people as of Tuesday morning, according to meteorological authorities.

A new round of sand and dust will affect at least 15 provinces and cities starting from Thursday. Another series of sand and dust events are predicted to occur from west to east in northern China between Thursday and Friday due to a new cold front forming, according to the national meteorological center.

There will be dust and sand spreading across China's Xinjiang region, Inner Mongolia and other regions, among which sandstorms are expected in some parts. From Thursday night to Friday, multiple regions including Beijing, Tianjin, Henan, northern Jiangsu and Anhui provinces, are predicted to experience sand and dust, with winds of grade 4 to 6. However, the impact range and intensity of this round of sandstorms will be significantly weaker than that of April 9 to 11, said China's national observatory.

In regions located in the Yellow River basin to the Yangtze River basin, environmental and weather authorities in multiple cities have issued alerts for approaching sandstorms, asking residents to make necessary preparations.

Hangzhou authorities released a warning on Wednesday morning to note that the PM 10 index in Hangzhou, capital of Zhejiang, was 485 as of 6 am on Wednesday, indicating serious pollution levels. Xu Bingye, an official at the Zhejiang Environmental Monitoring Center, said on Tuesday that the recent sand and dust pollution belt was expected to continue to move south through the Yangtze River Delta with the cold front, which was the fourth time that Zhejiang has been affected by dust. 

Between Tuesday night and Wednesday morning in Shanghai, the minimum visibility was about 3 to 5 kilometers due to the high concentration of the main pollutant, PM 10. Shanghai authorities on Tuesday night issued a warning for the approaching sandstorm and suggested residents limit prolonged outdoor exercise, especially key groups such as the elderly and patients with chronic diseases.

The sandstorm hit the Yangtze River region between Tuesday afternoon and Wednesday at noon, and it is expected to move away on Wednesday afternoon, Wu Rui, chief service officer at the Shanghai Meteorological Bureau, told the Global Times on Wednesday.

There are seasonal effects especially during the spring, a peak time for dust storms. Due to limited rain falling across Mongolia and North China's Inner Mongolia, a lack of new vegetation has exposed top soil and sandy areas, easily leading to sand and dust storms, according to Wu.

Some other regions including Anhui and Jiangsu issued similar alerts to remind people to take care when outdoors. The hashtag #sandstorm has been trending on Chinese social media since Monday evening.