  I discuss lattice QCD calculations of the properties of strongly interacting
matter at finite temperature, including the determination of the transition
temperature Tc, equation of state, different static screening lengths and
quarkonium spectral functions. The lattice data suggest that at temperatures
above 2Tc many properties of the quark gluon plasma can be understood using
weak coupling approach, although non-perturbative effects due to static
magnetic fields are significant in some quantities.
