Turnout in the municipal elections this year was historically low. It fell by four percentage points from the previous elections to just 55.1 percent.
Election experts interviewed by Yle said the low turnout was out of the ordinary.
"Yes, it is very unusual," said Professor Elina Kestilä-Kekkonen from the University of Tampere on a special election edition of Yle's breakfast show Ylen Aamu on Monday morning.
"The result is bad for democracy," said election expert Sami Borg from the University of Tampere.
Kestilä-Kekkonen told Yle voter turnout was likely the lowest since 1945.
According to Borg's calculations, fewer than a million eligible voters went to the ballot box on Sunday. The drop in the number of votes cast on election day was dramatic, Borg said, with only about 40 percent of all votes in the elections cast on Sunday.
"The lesson to be learnt from this is that elections should not be held on a summer Sunday," Borg said.
Borg also highlighted large differences in turnout between municipalities. In Kajaani, for example, turnout was well below 50 percent, while in Helsinki it was over 60 percent.
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The disparity in turnout was also seen within municipalities. Journalist Samuli Suonpää highlighted the gap in turnout between some traditionally working class neighbourhoods in outer Helsinki with that in wealthy areas closer to the city centre.
"Voter turnout in Helsinki: 40 percent in Jakomäki, Vesala, Kivikko, Vuosaari B.
"Over 70 percent in Ullanlinna. Töölö, Munkkiniemi, Kruununhaka 75 percent. Tammisalo, Suomenlinna 80 percent. Homeless voters 16 percent" he tweeted.
According to the experts, the low turnout was the biggest problem for the Finns Party, but the Social Democrats and Greens also suffered from the below average polling numbers. By contrast, the National Coalition Party (NCP) benefited.
"If voters failed to cast an early ballot, it is quite possible that they would not vote on a summer Sunday," said Kestilä-Kekkonen.
It is known from previous elections that those who are more confident about their choice of candidate tend to vote in advance.
According to Kestilä-Kekkonen, the low turnout explains to a large extent the NCP's victory in these municipal elections.
The elections were postponed from spring to summer and the early voting period was extended due to the coronavirus pandemic.