Its level at one measuring station fell to 18 centimetres (7 inches), beating the previous record set last year, by two centimetres, according to the IMGW weather institute.

According to IMGW forecasts, the water level will continue to fall until it reaches 12 centimetres -- 200 centimetres less than its average depth.

There has not been such a severe hydrological drought in Poland at this time of the year "since measurements began", Grzegorz Walijewski, hydrologist at IMGW, told AFP.

Walijewski said climate change was to blame, as higher temperatures and fewer rainfall days push down water levels.

The record comes a day after temperatures in Warsaw reached 36 degrees Celsius (97 degrees Fahrenheit), as part of a heatwave that has swept Europe.

Walijewski warned of the consequences of the drought, which "affects every branch of the economy".

He highlighted how the drought diminishes agricultural harvests and drives up food prices.

Outside of Poland, neighbouring countries have also been struggling with droughts.

"It's definitely a European problem, and in many instances a global one," Walijewski said.