The three provinces were Lampung, Bangka Belitung, and South Sumatra, Zakaria Ahmad of the Blang Bintang meteorology office, stated here, Monday.
Of the total 22 hotspots, four were believed to have arisen from fires.
Aceh was free from hotspots on Monday, but the province`s over 347 hectares of forest area were destroyed due to wildfires over the last two months.
Meanwhile, President Joko Widodo earlier remarked that land and forest fires had declined significantly this year as compared with previous years due to the country`s firm stance in protecting its forests.
"This assertiveness would not have yielded these ideal results without public support and participation," Widodo stressed in his presidential speech on the occasion of the 73rd anniversary of Indonesia`s independence at the parliament building in Jakarta on August 16, 2018.
The head of state expressed gratitude to the Indonesian military and police, local administrations, and the public for their dedication in preventing forest fires.
"We need courage to make the leap. We have to be firm in making the best decision for the people of Indonesia, including being firm in protecting our land and forests," he stated.
South Sumatra bore the maximum brunt of one of the country`s biggest forest fires in 2015 that ravaged the nation`s tropical forests in Sumatra and Kalimantan, sending haze of thick smoke as far as Malaysia and Singapore.
Environmentalists blamed farmers and plantation companies for the disaster that resulted in boycott of the country`s plantation commodities, mainly palm oil, by certain countries.
The government, however, has succeeded in reducing cases of forest fires over the past several years, although hotspots are still reported during drought that occurs almost every year.
Based on data of an Indonesian environmental NGO, Walhi, from January to August 14, a total of 2,173 hotspots were detected in various areas in the country, including 779 in West Kalimantan and 368 in Riau.
Reporting by Muhammad Said
Editing by Fardah Assegaf