Widespread heavy rain is sweeping over southern China. By Wednesday, rainfall totals are expected to exceed 100mm across many parts of Guangxi, Guangdong, Fujian, Zhejiang, Jiangxi and Hunan provinces, and in some areas as much as 150-200mm.

As a result, the Office of the State Flood Control and Drought Relief Headquarters and the Ministry of Emergency Management have been holding meetings with meteorological and hydrological departments to emphasise the importance of reinforced patrols and emergency responses to mitigate against the probable flooding that the intense rainfall is expected to bring. In particular, reservoirs with known safety concerns must remain empty during the period, as well as through the coming rainy season.

Torrential rain is also forecast this coming week for Bangladesh, northern Myanmar and the far east of India, including Nagaland, Manipur and Assam – up to 250mm could fall, locally more than 400mm.

Central and northern India are continuing to experience particularly high temperatures. Maxima of 45C have been reported from as far west as the coastal city of Surat, to Haryana and Delhi in the north, and Odisha in the east.

Combined with high humidity and extreme UV levels, several yellow heatwave alerts have been issued. The extreme sweltering heat is expected to last into the early part of the week, before somewhat cooler air arrives – with the potential for thunderstorms – bringing some relief.

Heavy rainfall has also been falling in Nigeria in recent days, causing widespread damage and destruction across some areas of Jalingo, the state capital of Taraba in the east of the country. On Saturday, intense rainfall led to a rapid rise in water levels that inundated properties and destroyed homes.

While rainfall totals were not as extreme as the levels being seen in south-east Asia, poor drainage infrastructure in Nigeria has meant that damaging flooding is an increasingly recurring issue.

Unseasonably cold weather is affecting central western Canada. The cities of Calgary, Edmonton and Saskatoon are all seeing daytime maximum temperatures below freezing and up to 15C below the normal for late April, while minimums of -10C to -12C are being experienced. The cold air has been bringing snow with the northern US states of Montana, Wyoming and North Dakota also affected. Much warmer conditions are expected to move in later this week, however, with the colder air moving into the southern and eastern US states.