We calculate the Seebeck S xx and Nernst S yx components of the thermopower tensor Ŝ in the quantum Hall system, using analytical formulas of the conductivity tensor $$\hat{\sigma}$$ that we deduced in a previous publication. The results basically reproduce the magnetic field dependence of experimentally observed behavior of S xx and S yx . With the aid of the Mott relation valid at low temperatures, we can further simplify the expressions and obtain analytical formulas for S xx and S yx . The Mott relation predicts that both S xx and S yx grow linearly with temperature T. To examine the range of validity of the formula based on the Mott relation, we investigate the temperature dependence of the height of the |S xx | peak at the first excited (N = 1) Landau level for various values of the impurity scattering time τ q. The results calculated with the more general integral formulas are seen to deviate from the linear T dependence and asymptotically approach the universal value (2ln 2/3)(k B/e) above $$T \simeq \hbar / (2 \tau_{\rm q} k_{\rm B}).$$