Temporal degree of freedom opens new capabilities to control electromagnetic interactions with structured media. While fast, comparable to the carrier oscillation period, changes in effective material susceptibilities suggest emerging new peculiar phenomena, experimental realizations of lag theoretical predictions. However, phenomena, inspired by slow practically realizable parametric changes in effective media, have both fundamental interest and immediate practical applications. Here we perform comprehensive studies of modal hierarchy in a deformable Fabry-Perot resonator, constructed from a wire array, hosted in a compressible dielectric host. The lattice parameter of the wire media can be controlled over a 5 -fold range (between 10 and 50 mm), leading to superior electromagnetic tunability. Furthermore, the resonator response demonstrates an extreme sensitivity to mechanical deformation as resonance hierarchy in metamaterial assembly strongly depends on the lattice constant. Specifically, a 0.3 mm change in the lattice constant, being as small as ∼ 0.002 λ, shifts the Fabry-Perot resonance frequency around 1.9 GHz. Owing to their extraordinary responsivity, deformable electromagnetic metamaterials can find use as elements in adaptive user-controlled devices.