Finite temperature magnetic properties of iron thin films are investigated, up to ferro/paramagnetic transition. The coupled dynamics of atoms and magnetic moments is treated using large-scale spin-lattice dynamics (SLD) simulations. A comprehensive study of surface and bulk magnetic properties is conducted, to investigate their dependences on temperature, film thickness, and crystallography of the film surface. We found that magnetization on the surface is enhanced at low temperatures, but is suppressed at higher temperatures, in agreement with experimental observations. The effective Curie temperature is found to decrease with the film thickness. Short-range magnetic order and non-vanishing spin-spin spatial correlations are observed above the Curie temperature. The spin autocorrelation functions exhibit slower oscillations with longer decoherence times near the surface. Directional spin disorder is found to have a significant effect on the surface strain.