Ice cover disappears from Lake Saimaa two weeks earlier than historical average

The ice on Finland’s Lake Saimaa has fully melted, marking one of the earliest breakups in over a century, according to data from the South-Eastern Finland University of Applied Sciences (Xamk).

Water systems expert Tapio Tuukkanen confirmed to public broadcaster Yle that both the smaller Pien-Saimaa and larger Suur-Saimaa basins are now ice-free. While the official ice-out date has yet to be recorded, Tuukkanen expects it to be determined within days. “This is clearly earlier than average, though not exceptional,” he noted.

Historical records from the Lauritsala measurement station in Lappeenranta, dating back to 1885, show the average ice-out date was previously May 2. Since 2000, however, the mean has shifted to April 20—a two-week acceleration over roughly a century. Climate projections suggest the trend may advance by several more weeks.

This year marks the fifth time since 2000 that Saimaa’s ice has cleared before mid-April, a phenomenon unrecorded before 1990. The earliest breakup occurred in 2020 (March 19), while the latest in recent years was May 6, 2022. Tuukkanen emphasised that while the long-term shift is evident, annual variation remains significant.