Two optical turbulence models, based on the Monin-Obukhov similarity theory, are used to estimate turbulence intensity C2n in atmospheric surface layer. The inputs to the models are the difference of temperature, specific humidity and wind speed taken from two heights above ground. Model results are compared with measurement of C2n with micro-thermometer. The difference of temperature ΔT is the most sensitive parameter. It is avoided to use roughness length, soil and sea surface temperature and specific humidity which are not easy to be measured accurately as input parameters. It is possible to estimate optical turbulence using historical data of standard meteorological parameters.