China is bracing for more extreme weather in coming days, bringing further risks to grain production across the nation.

While high temperatures in northern areas could affect corn planting and harm wheat crops, heavy rains are likely to hurt rice in key southern growing regions, according to a report from the National Meteorological Center.

The weather woes in the top importer of wheat, corn and soybeans come as drought threatens US crops, and heat waves melt glaciers and kill people in Asia. More disruption is looming from El Niño later this year. In China, heavy rains have already damaged wheat fields, while sweltering heat has stretched power grids, and the country is preparing for risks from widespread flooding.

Temperatures as high as 39C (102F) are expected in parts of northern China in the next few days, which could easily cause heat stroke among workers in the fields and accelerate loss of soil moisture, affecting summer planting. Farmers in the region usually plant corn after they have harvested wheat.

In parts of the northwestern region of Xinjiang, where some farmers have switched to growing grain rather than cotton under a government food security drive, fields of maturing wheat are now threatened by hot, dry winds.

Rains in many areas of southern China in the next 10 days are expected to be significantly higher than normal. While good for soil moisture, the rains increase flooding risks and can disrupt pollination of early rice, hurting yields.