Final ice melts in the Bay of Bothnia as Baltic Sea ice winter ends record early

The last remnants of sea ice in the northern Baltic Sea have disappeared, marking one of the earliest ends to the region’s ice season on record, Finland’s Meteorological Institute announced Sunday.

The institute’s ice service issued its final ice chart of the season on 10 May, confirming the entire Baltic Sea is now free of ice. The only earlier ice-free date in recent decades was in the 2014–2015 winter, when melting concluded around the same time.

This year’s ice cover peaked on 20 February, spanning 181,000 square kilometres—an unusually extensive freeze that mobilised all of Finland’s icebreakers. By comparison, the 2020 ice season saw just 37,000 square kilometres of coverage.

Niko Tollman, an ice specialist at the Meteorological Institute, attributed the rapid melt to extreme temperature swings. “The bitter cold in January and February created thick ice across all sea areas, but the unusually warm spring then weakened and dissolved it quickly,” he explained in a statement.

The Baltic typically remains ice-covered from late November to the end of May. Daily ice charts, produced jointly with Sweden’s meteorological agency, track conditions and icebreaker positions throughout the season.