The nationwide average temperature for last year was 4.5 degrees Celsius, the Finnish Meteorological Institute reports, which is 1.6 degrees higher than the long-term average for the years 1991–2020.
The shutdown comes as much of Finland is facing the coldest temperatures of the winter so far and some 800 households remain without power following a major storm last weekend.
Increased awareness of the dangers and widespread use of protective glasses have helped lower the number of firework-related eye injuries in recent years.
A low-pressure front moving in from the southwest could bring up to 40cm of snow as well as temperatures of -25C in some areas of Finland over the coming days.