Surat Thani is expected to make over 1.5 billion baht from tourists during the Songkran festival as other coastal provinces also look set to enjoy similar fortunes.
The celebration, which marks Thai traditional New Year, should at least draw nearly 10,000 visitors, mostly foreigners, during the five-day holiday, which began on April 12.
With their stay at hotels for 4.6 days on average and other spending both on mainland Surat Thani and its scenic resort islands, tourism revenues are most likely to hit the 1.5 billion-baht target, Suphakan Yotchun, chief of Tourism Authority of Thailand office in Surat Thani.
Among the province's big magnets were the Full Moon Party on Koh Phangan last Friday as well as the Water Colour festival held to mark Songkran festivity on Koh Samui until yesterday.
Up to 65% of tourists enjoyed the celebrations on beaches, Ms Suphakan said.
Songkhla, which has drawn the curtains on its two-day Midnight Songkran event in Hat Yai district, is also believed to have cash of up to 100 million baht flowing in the province during the period, local tourist guide Witthaya Sae-Lim said.
He based his estimate on average spending of tourists of between 4,000 and 5,000 baht each.
"Hotels, restaurants and Thai traditional massages attract them," Mr Witthaya said.
Revenues reaching 100 million baht are also expected in the eastern province of Chanthaburi as the number of Thai and foreign tourists increased by 60%, officials said.
Hotels, resorts and homestays were fully occupied as tourists flocked to celebrate the festival along Chao Lao and Khung Wiman beaches in Tha Mai district, they said.
In the Northeast, the Songkran mood is in full swing in Khon Kaen as officials encouraged Thai and foreign revelers to jointly create a "Thailand Human Wave" tonight along a 1.5-kilometre section of Si Chan Road, dubbed Khao Niao (sticky rice) road, in Muang district.
"We want to break the Guinness world record made by Japan," Khon Kaen mayor Thirasak Thikhayuphan said as people packed the street.