Belarus has a continental climate with cold winters and warm summers. The best time to visit depends on what you're after.
Summer (June–August) is the most popular season. Temperatures in Minsk average 18–24°C, with longer days and the best conditions for visiting Belovezhskaya Pushcha or Lake Narach. This is when the country feels most alive — outdoor cafes, festivals, and green parks. July and August can bring rain showers, but nothing sustained.
Spring (April–May) is attractive if you want to see the country at its most photogenic without summer crowds. The forests and wetlands are spectacular as they come back to life, and the light is good. Temperatures can still be cool in April.
Autumn (September–October) is underrated. The birch and oak forests turn gold, the air is crisp, and the tourist season has wound down. September is particularly good.
Winter (November–March) is cold — Minsk averages -5°C in January, and temperatures can drop to -20°C or below during cold spells. Snow covers the country from December to February. If you can handle the cold, winter has its own appeal: the Stalinist architecture looks striking under snow, and there are far fewer tourists. Cross-country skiing is possible in the national parks.
The Slavianski Bazaar in Vitebsk, one of the largest music festivals in Eastern Europe, takes place every July and draws large crowds to an otherwise quiet city.