The temperature dependences of the ESR spectra of nitrogen in the 1S(A(1)) and 1S(E) states were studied in n-type 6H SiC. The temperature dependencies of the line intensities and widths were used to determine ionization energies and the valley-orbit splitting of nitrogen on the cubic and hexagonal sites. The optical recharging of nitrogen in the paramagnetic 1S(AI) and 1S(E) states was observed after cooling the 6H SiC samples under interband illumination.