Aberdeen features an oceanic climate (Köppen "Cfb"). Aberdeen has far milder winter temperatures than one might expect for its northern location, although statistically it is the coldest city in the UK. During the winter, especially throughout December, the length of the day is very short, averaging 6 hours and 41 minutes between sunrise and sunset at winter solstice. As winter progresses, the length of the day grows fairly quickly, to 8 hours and 20 minutes by the end of January. Around summer solstice, the days will be around 18 hours long, having 17 hours and 55 minutes between sunrise and sunset. During this time of the year marginal nautical twilight lasts the entire night. Temperatures at this time of year hover around during the day in most of the urban area, though nearer directly on the coast, and around in the westernmost suburbs, illustrating the cooling effect of the North Sea during summer. In addition, from June onward skies are more overcast than in April/May, as reflected in a lower percentage of possible sunshine (the percentage of daylight hours that are sunny). These factors render both summer and winter temperate and mild for the latitude, both by European standards and those of far-inland climates on other continents.