Intensive baiting programmes have so far had little success against the infestation, and locals are hoping for heavy rain to drown the mice in their burrows.
It was hoped the whale would find its way out without help, as it did not initially appear to be in any distress.
Unusually heavy rains in Lapland have caused water levels to rise near flood levels, and further rises will depend on temperatures over the next few days, with climate change being a contributing factor.
The last time Finland had this much sunshine in March was nearly a decade ago, in 2013. High pressure typically brings clear skies, and this was also the case last month in Finland.
Harju said that due to its long tusks, she guessed that it was an older walrus, adding that the animal was calm during the hour that she watched it lay on the beach.
A minor earthquake, described by one resident as "a proper jerk", shook Rovaniemi. Dozens of earthquakes are observed in Finland every year. Typically, however, they are relatively weak, with a magnitude of less than 4.
Frost exposure and poor pollination are behind expectations for a less than ideal season, according to research institute Luke. Bilberry patches at particular risk are in the regions of South Karelia, Kainuu, Keminmaa, Ylitornio, as well as certain areas of Central and South Ostrobothnia.
The sale of fishing permits has been suspended for two sites where water temperatures have risen to critically high levels, especially for salmon.
Strong winds and heavy snowfall have led to flights being delayed, trains being cancelled, and motorists told to avoid unnecessary journeys.
Southern parts of the country can expect showers and thunderstorms on Tuesday, with more severe storms possibly hitting central areas by evening.
A mother and child lost their lives in an avalanche on Tuesday while skiing at Pallastunturi in northwestern Finnish Lapland.
May was also exceptionally dry in many areas. According to the FMI, Savukoski, a village in eastern Lapland, recorded the most rainfall last month with 59.4 millimeters.
The Food Authority noted that it might be possible that foxes are more susceptible to avian flu infections than mink. However, the agency also suggested that infection prevention protocols may not have worked as well at fox farms compared to facilities that raise mink. The authority has now confirmed avian influenza cases at a total of 42 fur farms in Finland.
One spark was all it took. The driver of the forest harvester was working a logging site at Renko in Kanta-Häme. The grapple of the machine hit a stone, throwing a spark that set the underbrush ablaze.
Finland is experiencing warm and sunny weather with temperatures ranging between 20 and 25 degrees Celsius, and an advisory for strong ultraviolet radiation has been issued for the south and southwest.
Firefighters dealt with about 20 blazes on Sunday alone, as dry conditions and strong winds heighten risks of forest and brush fires getting out of control.
There was a slight rise in population numbers of the very rare animals last year.
Early March's relatively mild start will get wetter in southern areas on Thursday, when a significant amount of rainfall is expected — with up to a full centimetre expected in western areas.
Temperatures in Finland last month were between 1.5 and 3.5 degrees Celsius warmer than normal in most parts of the country.
An elk was spotted swimming to the island of Utö in the Finnish archipelago, marking the first sighting of the animal in 40 years.
All Topics
All Countries
Any Date
Apply