Late spring (May and June) and early autumn (September and October) are the sweet spots, with mild days, blooming or golden parks, and fewer crowds. Summers are warm and sometimes hot (often into the low 30s Celsius) but Sofia sits at 550 meters, so evenings cool off and the mountains stay pleasant for hiking, making July and August prime day-trip season for the Seven Rila Lakes. Winters are cold and snowy, which turns nearby Vitosha and Borovets into working ski areas within an hour of the center. If you want a festival, aim for the Sofia International Film Festival in March or the open-air concerts and terraces of summer.

Sofia Airport (SOF) sits about 10 km east of the center; the cleanest way in is Metro Line 1 (M1/M4), roughly 30 minutes to Serdika station and under 2 leva, or a metered yellow taxi (only use OK Supertrans or book via the Yellow!/Maxim apps to avoid airport-taxi scams, usually 15-20 leva). Central Sofia is flat and walkable, and the two-line metro is fast, cheap, and reaches the airport and both main stations. For everything else, ride-hail through the TaxiMe or Yellow! apps is transparent and inexpensive; avoid hailing unmarked cars off the street. Bulgaria uses the lev (BGN), though euro adoption is on the horizon, so carry some cash for small cafes and markets.