Latvia is located in a temperate climate zone and weather conditions are determined by the Atlantic air masses, the Baltic Sea and the Riga Sea Gulf stretching deep into the country. Climate is characterized by a periodic influence of high- and low-pressure centers and a comparatively high precipitation. Weather in Latvia is inconsistent and hardly predictable. Precipitation can be expected 180 days per year – on average every other day (in summer it rains rarely, during autumn it rains more often, but in winter it may snow every day). Average amount of precipitation is 500 – 800 mm per year.  Summers are sunny and warm with an average temperature of +19ºC; the hottest months are July and August.   During spring and autumn weather is variable and generally humid with the average temperature around +10ºC.  In winter snow falls from December until March, the coolest month is January, with the average temperature -6ºC.  Length of the day in Latvia in winter is around 6-7 hours, in summer 17-18 hours, depending on the location of the sun over the horizon.