The Election Commission (EC) said it expects to have the results of the Provincial Administrative Organisation (PAO) elections by 10pm.
The PAO elections are being held on Saturday in 76 provinces.
Only 49 provinces expect to see both their PAO chiefs and members elected on Saturday, however.
Voters in 29 other provinces are to elect only their PAO members, as their PAO chiefs have already been elected following the early resignations of their predecessors.
The four-year term of all PAO chiefs ended on Dec 19.
EC Chairman Ittiporn Boonpracong said on Friday during his visit to Chiang Mai to inspect the province's preparedness for the election, that the EC has made sure all election officials are experienced and well-trained to meet the right standards.
When asked if Chiang Mai would be watched more closely as the main parties have been actively campaigning there in the final days, Mr Ittiporn said that all candidates were aware of the election rules.
The EC provides a campaigning handbook to guide candidates on what is permitted. If any potential transgressions are feared, candidates can consult the EC, he noted.
He said there have been 153 election-related complaints in Chiang Mai so far -- mostly involving vote-buying, community donations, entertainment events, campaign violations and false accusations.
The number of complaints is far lower than during the PAO election in 2020 when 718 complaints were filed.
Regarding allegations of paying people to attend campaign rallies, Mr Ittiporn said that the EC requires solid evidence before taking legal action on such matters.
Evidence, such as photos, audio recordings and fingerprints, is crucial in proving misconduct, he said.
Eight election inspectors and eight assistants are monitoring the situation in Chiang Mai, along with rapid response teams to gather evidence if and when needed.
The EC has collaborated with provincial governors and police to intensify security measures, including setting up inspection checkpoints during the last three days.
Mr Ittiporn encouraged people nationwide to participate in monitoring the election process to help prevent fraud.
The EC will do its best to carry out its duty, he said.
In the previous PAO elections, Chiang Mai was among the provinces with the highest voter turnout of 77.95%, while Lamphun was close behind at 77.86%.
"This year, we aim for 75 to 80 per cent turnout," said Mr Ittiporn.
In smaller provinces, results should be finalised by 10pm.
However, in larger provinces like Chiang Mai, where some polling stations are far from counting centres, the process may take longer.