Kemijärvi water level swings six metres in a month from dry to near flood stage

The water level in Lake Kemijärvi has fluctuated by six metres in less than a month, shifting from exposed lakebed in early May to near the upper regulation limit ahead of forecasted heavy rainfall, Finnish broadcaster Yle reports.

Hydro operator Kemijoki Oy has increased discharge flows in anticipation of exceptional downpours expected over the weekend, which could push water levels higher. While no immediate flooding threats have been identified, residents along the riverbank have been advised to prepare for potential damage to docks and other structures if flows rise further.

“This is still flood season,” said Heikki Poikela, Kemijoki Oy’s continuity management director. “Right now, it doesn’t look like the riverbanks will be at risk, but that depends entirely on how the rainfall materialises. The forecasts do look exceptionally severe.”

The abrupt shift follows an unusually early spring melt that began in March, leaving the lake at historically low levels just weeks ago. At that time, the exposed lakebed was visible enough that fishing lures could be collected by hand. Poikela linked the volatility to broader climate trends, noting that measurements confirm increasing extreme weather patterns—earlier springs paired with heavy rainfall during thaw periods.

“This aligns directly with earlier climate projections,” he said. “Spring starts sooner, and major rainfall events coincide with the melt. The climate is changing.”