Due to its latitude, Tallinn has 19 hours of daylight in summer, while in winter it only has 6 hours.

An excerpt from the article 27 facts about Tallinn

Winters in Tallinn are very cold and dark with little rainfall, spring is cool and dry. Summer is moderately hot and rainy, and autumn is a season of heavy rainfall, which, combined with the rapid melting of the first snow, causes mud to form in undeveloped areas.