We report EPR and magnetic measurements of diaqua-(pyridine-2,6-dicarboxylato)Copper(II) together with computational calculations. This compound consists of an extended lattice of magnetically equivalent copper(II) ions in which the copper centers are linked by hydrophobic interactions such as π⋯π, π⋯metal, and Y–X⋯π, and hydrogen bonds involving different topologies, viz., [sbnd]Cu[sbnd]O_eq⋯O_eq[sbnd]Cu[sbnd], [sbnd]Cu[sbnd]O_eq⋯O_ap[sbnd]Cu[sbnd], and [sbnd]Cu[sbnd]O_eq⋯O[dbnd]C[sbnd]O_eq[sbnd]Cu[sbnd]. The powder EPR spectrum shows nearly axial symmetry with non-resolved hyperfine structure with the copper nucleus, suggesting the presence of intercenter isotropic exchange interactions. Single crystal EPR experiments show a single lorentzian resonance line for all the magnetic field orientations investigated, typical of an extended exchange coupled system. Susceptibility measurements showed weakly antiferromagnetically coupled Cu(II) ions (J = -0.79 (4) cm^-1). Using Anderson's exchange narrowing model for the collapse of the hyperfine structure, EPR yielded |J| = 0.6 (1) cm^-1. The distinct contributions of the different chemical pathways to the experimentally determined J-value are analyzed through first principle computational calculations.