The Tourism Council of Thailand (TCT) expects 9.1 million foreigners to visit Thailand in the second quarter of 2018, up 11.9% from the same period last year.
Key reasons cited for the growth are the global economic recovery and attractive campaigns promoted by the public and private sectors.
In the first quarter, 9.84 million foreign tourists visited Thailand, up 7% year-on-year, according to TCT president Ittirit Kinglake.
Markets providing large numbers of visitors included Southeast Asia (2.66 million, up 10.4%); East Asia (3.74 million, up 12.5%); and Europe (1.25 million, up 10.6%).
Inbound tourism continues to grow because of the rebounding economies of many countries, Mr Ittirit said.
If tourism growth proceeds at its current pace, he said, the expectation is for total international arrivals to reach 38.93 million in 2018, or a 9.2% year-on-year increase.
Such an inflow would generate tourism income of 2.14 trillion baht, up 17.4% year-on-year.
Domestic tourism growth is also anticipated, as TCT statistics show that 25% of local people planned to travel in the first quarter and 33% expect to make trips in the second quarter because of the long holiday period, especially during Songkran in April.
According to Mr Ittirit, the TCT has urged the government to improve infrastructure and logistics in order to accommodate tourists and improve accessibility.
Government bodies involved in the tourism sector were asked to renovate damaged attractions, enhance human resources and develop new tourism products and services.
The TCT suggested tourism operators raise brand awareness for the sake of the country's tourism industry by securing international standards such as Green Leaf (for environmental awareness) and lifting hotel ratings.
The agency also recommended that entrepreneurs and local communities improve the quality of their products and create attractive packages to expand the marketplace.
Supawan Tanomkieatipum, president of the Thai Hotels Association (THA), said all major tourist destinations in Thailand will be crowded with locals and international tourists during Songkran.
Hotels in popular tourism spots, such as Khao San Road and Silom Road in Bangkok and the northern city of Chiang Mai, are overbooked for the festival, which starts April 12 and ends April 16.
Most hotels, however, are unable to increase their room rates despite the peak period, due to fierce competition.
Ms Supawan said average room rates for hotels in Thailand are lower than those in Singapore, Vietnam and Myanmar.
"Hotels in Singapore are priced at more than US$180 or 5,940 baht per night, while in Thailand hotels are rated at $150 or 4,950 baht per night," she said.
Yuthasak Supasorn, governor of the Tourism Authority of Thailand, said the tax break scheme for tourism spending in 55 secondary provinces this year will help increase the number of tourists travelling to these provinces to about 10 million, up 20% from 2017.
The tax breaks, effective from Jan 1 to Dec 31, 2018, will be offered to individual travellers who spend on accommodation, food and drinks, as well as to corporations that organise seminars and meetings in the secondary provinces, which welcome fewer than 4 million tourists a year.