Freezing began in the Bay of Bothnia on November 4. Due to the mild weather, ice formation progressed very slowly. A month later, thin ice was formed along the northern coast of the Bay of Bothnia and in places in the Vaasa archipelago. By mid-December, the inland bays in other parts of the country also began to freeze. The first icebreaker, Kontio, began to operate on December 22, when the ice thickness in the Bay of Bothnia had reached 15 cm.

At the turn of the year, frost strengthened the ice cover, but the ice-covered area didn´t grow as fast as during the previous season. When the weather turned mild in mid-January, the amount of ice did not increase significantly. The mild weather and several windy days prevented ice formation in the open sea, and apart from the Bay of Bothnia, most sea areas remained largely ice-free. By the end of the month, the ice extent was less than 30,000 km², clearly below average.

Although local temperature records for February were broken in northern Finland during the first half of the month, the Bay of Bothnia became fully ice-covered only on February 15. Mid-February brought the only significant cold spell of the month, and the winter’s maximum ice extent–85,000 km²–was reached on February 20. Still the icebreakers were needed only in the Bay of Bothnia.

After that, a mild southwesterly airflow pushed the ice field in the Bay of Bothnia together, and a large open water area formed north of the Quark on the Swedish side of the bay. This situation persisted until the end of winter, except for a few colder periods in March, when thin ice was formed in open areas. By the end of a record-warm March, the ice extent had shrunk to 17,000 km². For comparison, the smallest March ice extent between 2008 and 2022 was 10,000 km².

The Gulf of Finland and the Bothnian Sea were already ice-free by April 7. Some rotten fast ice remained in the Vaasa archipelago. In the Bay of Bothnia, for most time of the month, the edge of the ice field in the middle of the Bay of Bothnia ran from Kalajoki toward Luleå. North of this line, the ice field was packed and difficult to force. In March and April there were several strong southwesterly winds, and despite the small ice-covered area, icebreakers were still needed to keep traffic moving. By the end of April, the ice began to retreat. After the coastal fast ice melted in mid-May, the last drift ice off Kalajoki disappeared, and the Baltic Sea was ice-free by May 23. The icebreaker Polaris ended its assistance operations a few days earlier.

The thickness of the fast ice ranged from 5 to 20 cm in the Gulf of Finland and the Bothnian Sea, from 20 to 45 cm in the Quark, and 40 to 80 cm in the Bay of Bothnia. Drift ice thickness in the Bay of Bothnia varied between 30 and 70 cm. In the Quark, the Bothnian Sea, and parts of the Gulf of Finland, thin ice was formed occasionally in offshore areas.

In the Bay of Bothnia, the ice season began about one and a half weeks later than usual and ended from one and a half to four weeks earlier than normal. In the Quark, the ice season began approximately at the usual time–earlier along the coast but slightly later offshore. The ice season ended two to five weeks earlier than average in the Quark.

In the Bothnian Sea, ice was present only in coastal areas and persisted for just over a month at most. No ice was observed in the northern Baltic Sea or the westernmost parts of the Gulf of Finland. In the central and eastern Gulf of Finland, ice appeared for only about a week. Across all sea areas, the number of actual ice days was lower than usual.