The Guardian - China-Weather tracker Contrasts in cold and heat break records in China

China’s Xinjiang region, in the far west of the country, experienced record-breaking low temperatures of -52.3C on 18 February, surpassing a 64-year-old record for the region. The figure was just shy of the lowest national temperature of -53C, which was recorded in the Heilongjiang region in January last year.

The extreme weather has caused big disruption after the lunar new year celebrations, with blizzards and ice leaving people stranded on roads and railways. On the same day, Badu in the south of China recorded a maximum temperature of 38C, meaning there was a staggering temperature difference of 90.3C across the country. This is the largest temperature contrast ever recorded for a single country, surpassing the US in January 1954 by a whole degree Celsius.

In the same week, a weather system off the coast of south-eastern Brazil had strengthened to form Tropical Storm Akará. On 18 February, the Brazilian Navy Hydrographic Center reported that Storm Akará had formed overnight with sustained wind speeds of 40mph and a pressure of 1,000 millibars.

Unlike in the north Atlantic, it is a rare occurrence for tropical cyclones to form in the southern hemisphere due to strong wind shear and a lack of favourable weather disturbances for development. Akará is the first named tropical storm to develop in the south Atlantic Ocean since Tropical Storm Iba in 2019, and only the third since Anita in 2010. Furthermore, Hurricane Catarina in 2004 still stands as the sole recorded south Atlantic hurricane in history.

Akará was able to develop from the remnants of a cold front that had brought heavy rain to parts of South America before pushing offshore. The low-pressure system rapidly deepened into a tropical storm as it moved over warmer waters and was also fed by a plume of tropical moisture that moved southwards down the Brazilian coast. The storm did not bring a threat to the mainland as its trajectory was moving south-west over the Atlantic Ocean, but the Brazilian National Institute of Meteorology was forecasting marine impacts with offshore waves of up to 4.9 metres (16ft) and winds of up to 50mph. By Tuesday, the Brazilian navy reported that the storm had weakened into a tropical depression as it continued to move away from mainland Brazil. The system weakened further on Wednesday as it travelled over cooler waters well offshore from the mainland.