The two best times to visit Xanthi are during the Carnival (February or March, two weeks before Clean Monday) and the Old Town Festival in early September. The Carnival is one of the biggest in Greece, with parades, costumes, and a boisterous atmosphere. The Old Town Festival fills the upper town with music, craft stalls, and outdoor performances over a long weekend.
Outside festival periods, spring and early autumn are the most comfortable for walking the old town. Summer is hot and the student population disperses; the city is quieter but perfectly functional. Winters are cold by Greek standards — Xanthi sits inland in Thrace and can have heavy snow in January and February.