Shanghai recorded its hottest May day in 100 years on Monday, the city's meteorological service announced, shattering the previous high by a full degree.

Scientists say global warming is exacerbating adverse weather, with many countries experiencing deadly heatwaves and temperatures hitting records across Southeast and South Asia in recent weeks.

"At 13:09, the temperature at Xujiahui station hit 36.1 degrees Celsius (97 degrees Fahrenheit), breaking a 100-year-old record for the highest temperature in May," a post on the service's official Weibo account read, referring to a metro station in the centre of China's largest city.

The temperature at the bustling station climbed even higher to 36.7C (98F) later in the afternoon, Shanghai's meteorological service said.

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

Shanghai residents sweltered under the early-afternoon sun, with some apps showing a "feels like" temperature estimate of more than 40C (104F).

"I headed out at noon to pick up a delivery, and got a headache after coming back," read one post from Shanghai on Weibo.

Another said: "I almost got heatstroke, it's really hot enough to explode."

- Deadly heat -

Parts of India saw temperatures above 44C (111F) in mid-April, with at least 11 deaths near Mumbai attributed to heat stroke on a single day.

In Bangladesh, Dhaka suffered its hottest day in almost 60 years.

The city of Tak in Thailand recorded its highest-ever temperature of 45.4C (114F), while Sainyabuli province in Laos hit 42.9C (109F), an all-time national temperature record, the study by the World Weather Attribution group said.

A recent report from the UN's Intergovernmental Panel on Climate Change warned that "every increment of global warming will intensify multiple and concurrent hazards".

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 gasses 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 (WMO) said.

The 2015 Paris Agreement saw countries agree to cap global warming at "well below" two degrees Celsius above average levels measured between 1850 and 1900 -- and 1.5C if possible.

The global mean temperature in 2022 was 1.15C above the 1850-1900 average.

The WMO said there was a 66 percent chance that annual global surface temperatures will exceed 1.5C above pre-industrial levels for at least one of the years from 2023-2027.