Humans have already endangered their shared cultural heritage by amplifying extreme weather events

• Novel application of attribution science to cultural heritage for the first time. • Identifies human contributions to changes in extreme weather events at WHSs. • Reveals risk variation across extreme heat, dry spells, and heavy rainfall globally. • WHSs in lower-income countries face increased heat hazards and higher vulnerability. • Future projections show intensifying heat and wider wet dry contrasts at WHSs. World Heritage Sites (WHSs) hold international cultural, historical, or scientific significance. The frequency and severity of extreme climate events at these sites are changing, but the extent to which this is attributed to human activity is unknown. To address this, we conduct an attribution study for three climate extremes for all WHSs inscribed with cultural value. As of the early 21st century, human activities have on average increased extreme heat days by 46 per year at WHSs. Consecutive dry days intensified in WHS-dense Mediterranean regions, while changes in extreme rainfall were highly regional. WHSs in low-income countries experience the highest contribution of human activity to extreme heat days, in contrast to predominantly low-to-moderate contributions for WHSs in high-income regions. By showing how human-driven climate extremes vary at WHSs globally, we demonstrate how attribution studies can inform international policy coordination and site-level adaptation for cultural heritage.