Finland's heatwave will continue through to the end of the week, with temperatures expected to climb as high as 32 degrees Celsius in western Lapland, according to the Finnish Meteorological Institute (FMI).
Thursday's weather remains clear throughout the country, although isolated showers are possible in southern regions during the afternoon.
The FMI has issued a heat warning for much of southern Finland, where daily highs are expected to reach at least 27 degrees and average daily temperatures 20 degrees — thresholds for a so-called "oppressive heat" alert.
Western Lapland is forecast to experience the hottest conditions across the country later in the week.
Cyanobacteria returns
The prolonged warm weather has also led to an increase in cyanobacteria, or blue-green algae, the Finnish Environment Institute (Syke) reported. Additionally, early summer rains and winds have also created favourable conditions for blue-green algae blooms.
The blooms have expanded in both inland waters and along coastal and open sea areas.
This week, significant concentrations were observed at seven inland monitoring sites in Pirkanmaa, Kanta-Häme, Päijät-Häme, Southwest Finland, Kainuu and North Ostrobothnia.
Slight algae presence was noted at 49 other inland sites, mostly in southern and central Finland, with some sightings also reported in Lapland.
On the coast, very abundant blooms were observed at three sites in Southwest Finland, while high levels were also recorded along the shores of Uusimaa and Southwest Finland.
