Strong winds blew tents away as heavy rain arrived following a heat wave in Thailand.

Video shows a raging storm battering the Hathairat Gym in Bangkok on April 25, with the fierce winds blowing two tents away.

Onlooker Pakin Mueangsuk said: 'The rain was so strong, it was terrifying. Luckily, no one was hurt when the tents flew away.'

The storm came as temperatures soared past 42 degrees Celsius last week during a heat wave across the Asia Pacific region.

Maximiliano Herrera, a climatologist and weather historian, described the scorching heat as the 'worst April heatwave in Asian history'.

In Thai capital Bangkok, residents were warned not to go outside amid 42 degrees Celsius temperatures causing power outages due to surging demand from air con units and fans running.

The country's national weather service said the heat index - what the temperature feels like when combined with humidity - hit a record 54C (129F).

The warm weather is now giving way to extreme tropical storms.

The Thai Meteorological Department warned that southerly and southeasterly winds prevailing over upper Thailand would strengthen between April 23 and 26.

Outbreaks of summer storms, accompanied by thunderstorms, gusty winds, hail, and lightning strikes, were expected to affect the northeastern and eastern parts of the country first, before spreading to other regions.