Humidity increases in September, morning fogs are known

kick off morning fog reduced visibility in Helsinki early in the morning and early afternoon on Thursday.

Similar thick fog was also observed in other parts of Finland in lake regions and near riverbanks, says the meteorologist of the Finnish Meteorological Institute Eetu Rimo.

Morning fogs become more common in autumn. There is more and more moisture in the air, and the air temperature is approaching the dew point.

Helsinki in the region, on Thursday morning, the wind also blew from the south from the sea and brought moist air over the city.

The temperature is colder in land areas than in the sea. Therefore, the moisture flowing from the south condenses on the ground into fog.

The fog dissipates at the latest in the morning or immediately after the sun starts to warm the air, says Rimo.