Summers can get very hot, particularly at lower levels, making the Black Sea the place to be for local holiday makers. Although autumn has cooler temperatures, it's one of the best times to visit Bulgaria for country walks and city sightseeing. Spring can get be wet with most rainfall in May and June. This is the best time to visit the glacial lakes, mountain streams and waterfalls. In winter, Bulgaria's alpine areas are covered in snow with ski resorts close to Sofia and Plovdiv.