The capital city's balmy temperatures and high humidity have caused sleepless, sweaty nights for many residents.
Many of Helsinki's apartment buildings are ill-equipped to deal with this summer's heat wave.
Some people have fled their hot flats for cooler hotels, for example Hotel Helka in downtown Helsinki, according to the hotel's manager, Jukka Räisänen.
He said more than a few of the hotel's recent guests have been locals who live on the same street as the hotel itself.
As they make their booking, these guests - often elderly people - immediately ask whether the hotel rooms are air conditioned.
"Older people who live in old, brick buildings in the Töölö neighbourhood have gravitated our way this summer," Räisänen said.
Each room has a thermostat which can be adjusted to the guest's preference, he said.
"We dial in the temperature so that it is pleasant when the guest arrives. Then they can adjust it to their liking," he said, adding that this isn't the first year locals have sought refuge from the heat.
Overwhelming heat is not the only reason locals decide to stay at nearby hotels. Often city dwellers book hotel rooms during the Christmas season for holiday parties, and then there are new parents with fussy babies who are looking for a good night's rest, Räisänen said.