At least a hundred monkeys climbed down a hill to cool off in a pool of water at Wat Tham Sue in Krabi on Sunday.
Krabi has not seen rain for about two months and this particular area has experienced a severe rise in temperature.
"The monkeys climbed down into the pool, close to where tourists had come down for refreshments. Everyone was delighted to be able to enjoy a surprise appearance by the 'guests'," Jamras Sornsuvann, the temple keeper, told the Phuket Gazette.
The monkeys playfully splashed around in the water and smiled at tourists as they took pictures.
Jamras warned people to be careful, adding that monkeys become aggressive in hot weather and could end up biting someone.
"Do not feed them, as they are naturally able to procure food for themselves," he warned.
He also noted that tourists should only take photos, and not touch, play with or provoke the monkeys in any way.