Tartu in April

May through September gives you the best weather and longest days. July means White Nights — sunset around 10:30pm with hours of golden light. But it also means crowds of Estonian families on holiday. June hits the sweet spot: warm weather, fewer tourists, and the academic year winding down. September brings students back, filling the pubs with energy again. Winter is brutal — temperatures drop to -15°C and daylight lasts maybe six hours. The Christmas market tries to compensate, but you'll spend most of your time indoors. Spring arrives late but dramatically. One day it's gray and cold, the next week everything's blooming.