Frost in winter can produce quite wonderful lighting effects.
As an example, since Tuesday night, Lahti residents have been actively sharing images of vertical light poles from street lights across the city.
"The phenomenon is reminiscent of floodlights that were used to detect planes in the sky during the war." I show Hannu Valta, A meteorologist from the Finnish Meteorological Institute describes them.
Power added that a similar light phenomenon can be seen during the winter frosts at sunset.
These light pillars are created when the moisture in the air turns directly into ice crystals. According to power, the crystals are hexagonal and pillar-like. They can reflect the light from street lamps as they descend very slowly towards the ground.
"Against the horizon, it looks like a floodlight pointing upwards," he explains.
The phenomenon requires temperatures of -20 degrees Celsius or colder. The sight is seen more often in the northern parts of the country than in southern Finland, where there are fewer such conditions.