The high-precision spectroscopy of atoms in optical lattices requires a detailed account for the influence of external factors on atomic properties. Together with the lattice radiation, an important irremovable perturbation on the positions and widths of atomic energy levels may be imparted by the ubiquitous blackbody radiation (BBR) of environment. To effectively control this perturbation, the parameters of the BBR should be known with essential precision, together with the dependence of atomic properties on the BBR characteristics. The basic characteristic of the BBR is its temperature. Therefore high-precision determination of the BBR temperature is an important problem for fundamental measurements of spectroscopic parameters in atoms confined to an optical lattices, in particular, for the lattice-based time and frequency standards .