Potenza's altitude — over 800 metres — gives it a climate closer to a small alpine town than to the typical southern Italian city. Winter is genuinely cold; snow is common from December to March and the streets can ice over.
Spring and autumn are mild and lovely; summer is warm (highs in the high 20s) but pleasantly cool at night when the rest of southern Italy is sweltering. The big local event is the Parata dei Turchi on 29 May, a colourful pageant commemorating a 16th-century Saracen raid that the city's patron saint reputedly saw off. Worth timing a visit around.