Shanghai on Monday recorded its hottest May day in a century, the city's meteorological service announced, shattering the previous high by a full degree.

"At 13:09, the temperature at Xujiahui station hit 36.1 degrees Celsius, breaking a 100-year-old record for the highest temperature in May," a post on the service's official Weibo account read.

Scientists say global warming is exacerbating adverse weather, with a recent report from the UN's Intergovernmental Panel on Climate Change warning that "every increment of global warming will intensify multiple and concurrent hazards".

Later in the afternoon, the temperature at the metro station in central Shanghai climbed even higher to 36.7 degrees Celsius, the meteorological service said.

That put it a full degree above the old record, 35.7 degrees Celsius, which has been recorded four times previously – in 1876, 1903, 1915 and 2018, according to the weather service.

In May the United Nations warned that it is near-certain that 2023-2027 will be the warmest five-year period ever recorded, as greenhouse gases and El Nino combine to send temperatures soaring.

There is a two-thirds chance that at least one of the next five years will see global temperatures exceed the more ambitious target set out in the Paris accords on limiting climate change, the UN's World Meteorological Organization said. (AFP)