Latvia has four pronounced seasons of near-equal length. Winter starts in mid-December and lasts until mid-March. Winters have average temperatures of  and are characterized by stable snow cover, bright sunshine, and short days. Severe spells of winter weather with cold winds, extreme temperatures of around  and heavy snowfalls are common. Summer starts in June and lasts until August. Summers are usually warm and sunny, with cool evenings and nights. Summers have average temperatures of around , with extremes of . Spring and autumn bring fairly mild weather.