Lake Päijänne: The Largest Lake in Finland

Overview and Statistics

Lake Name: Lake Päijänne

Country: Finland

Surface Area: 1,083 square kilometers

Maximum Depth: 95 meters

Average Depth: 16 meters

Lake Type: Natural

Length: 120 kilometers

Catchment Area: 25,400 square kilometers

Altitude: 78 meters

Volume: 18.1 cubic kilometers

Outflows: Kymi River

Islands: 1,886 islands, including Virmailansaari, Salonsaari, Judinsalo, Onkisalo, Paatsalo, Muuratsalo, Haukkasalo, Vuoritsalo, Mustassalo, Edessalo, and Taivassalo

Shore Length: 1,140 kilometers

Mixing Type: Dimictic

Settlements: Asikkala, Jyväskylä, Korpilahti, Kuhmoinen, Luhanka, Muurame, Padasjoki, Sysmä

Frozen Period: December to May

Trophic State: Oligotrophic

Geography and Geology

Lake Päijänne is renowned for its intricate geography, characterized by thousands of islands. Some of the largest islands include Virmailansaari, Salonsaari, Judinsalo, and Muuratsalo. The lake’s open water areas, such as Ristinselkä, Vanhanselkä, Tehinselkä, and Asikkalanselkä, offer vast and tranquil vistas.

The lake is Finland’s deepest, with a maximum depth of 95 meters. Its irregular shoreline and dense forested surroundings make it a hub for timber transportation. Lake Päijänne’s origin lies in the land uplift following the last Ice Age, shaped by ancient faults in the bedrock. The predominant geological composition includes Precambrian granite and gneiss, which form the foundation for its sandy beaches.

Climate

The region experiences four distinct seasons. Winter temperatures can plummet to -15°C to -20°C, while summer brings milder conditions with averages of around 20°C. Peak summer temperatures can reach up to 25°C to 27°C. The area’s long daylight hours, especially in summer, make it an appealing destination for outdoor enthusiasts.

Transportation

Dear Lykkers! Lake Päijänne connects to several nearby lakes, including Kertele, Vesijärvi, and Ruotsalainen, through canals. Historically, it was a major transportation hub in central Finland. Although its role in freight and passenger transport has diminished, the lake now caters to tourism, with scenic boat tours being a prominent feature.

A notable infrastructure highlight is the Päijänne Water Tunnel, an underground aqueduct linking the lake to Helsinki. This tunnel is a vital water source for Finland’s capital city.

Tourism and Recreation

Lake Päijänne is celebrated for its pristine waters and diverse recreational opportunities. Its clear waters and abundant fishing grounds attract anglers, with species like pike, perch, zander, and brown trout thriving in its bays and open waters. Popular water sports include boating, canoeing, and sailing.

The Päijänne National Park, established in 1993, spans 14 square kilometers and is situated in the lake’s southern region. It features sandy eskers, isolated lagoons, and small islets, making it a haven for nature enthusiasts. Another nearby gem is the Leivonmäki National Park, offering marked trails and scenic viewpoints.

Bird-watching is a favored activity, with ducks, geese, herons, and other species commonly spotted. Nature lovers can also explore the region’s flora, including wild berries, mushrooms, and over 300 plant species such as heath spotted orchids and water forget-me-nots.

Interesting Facts

Surface Area: 1,100 square kilometers

Volume: 17.8 cubic kilometers

Maximum Depth: 98 meters

Mean Depth: 17 meters

Water Level Regulation: Controlled

Annual Water Level Fluctuation: Approximately 1 meter

Shoreline Length: 1,140 kilometers

Residence Time: 2.7 years