Abstract <p>We investigated the mechanical response of planar auxetic lattice metamaterials with various cell geometries under thermal loading. The dependance of the structures’ deformation behavior on both the geometry and quantity of the unit cells was established. Specifically, the influence of unit cell shape (auxetic and trapezoidal) and connecting element type (straight and arc) on thermal expansion was analyzed. The obtained results can be used for designing metamaterials with tailored thermomechanical response.</p>