A stress-induced stripe phase of submonolayer Pd on W(110) is observed by low-energy electron microscopy. The temperature dependence of the pattern is explained by the change both in the boundary free energy and elastic relaxation energy due to the increasing boundary width. The stripes are shown to disorder when the correlation length of the condensed phase becomes comparable to its period, while the condensate to lattice-gas transition takes place at a higher temperature, as revealed by low-energy electron diffraction.