Global climate change is exacerbating biological invasions; however, the roles of genomic and epigenomic variations and their interactions in future climate adaptation remain underexplored. Using the model invasive ascidian Botryllus schlosseri across the Northern Hemisphere, we investigated genomic and epigenomic responses to future climates and developed a framework to assess future invasion risks. We employed generalized dissimilarity modeling and gradient forest analyses to calculate genomic and epigenomic offsets under climate change. Our analyses revealed that genomically and epigenomically maladapted populations did not geographically coincide, suggesting complementary interplays of these variations in climate adaptation. By integrating both types of offsets, we predicted that populations with lower genome-epigenomic indices were less maladapted, indicating higher future invasion risks. Native populations exhibited lower offsets than invasive populations, suggesting higher adaptive potentials and invasion risks. These results highlight the importance of incorporating multiomics data into predictive models to study future climate (mal)adaptation and assess invasion risks under global climate change.

invasion risk, climate change, (epi)genomic variation, (epi)genomic offset, climate (mal)adaptation