pakkasta

Pakkasta is a Finnish term for freezing temperatures or frost. In ordinary language and meteorology, it describes conditions when the air temperature is at or below 0 degrees Celsius. The form pakkasta appears in phrases like “on pakkasta” (“it’s freezing”), and is linked to pakkanen, the noun for frost or a cold spell.

Pakkasta results from radiative cooling of the Earth's surface, especially on clear, calm winter nights when heat is lost to space. Snow cover and wind influence how cold it feels. The phenomenon is typical of Nordic climates and varies with location, altitude, and season.

Temperatures labeled as pakkasta in Finland vary by region. In the south, winter nights commonly reach roughly −5 to −15 °C, while central and northern areas often see −15 to −25 °C. In Lapland, extreme cold snaps of −30 °C or colder occur occasionally.

Freezing temperatures have practical effects: increased risk of frostbite for people outdoors, frozen pipes and frosting on windows, and impacts on crops and infrastructure. They also raise energy demand and can affect safety in road and rail transport.

See also: pakkanen, frost, cold snap. Pakkasta is widely used in weather forecasts and everyday speech to describe cold winter conditions.