Temporal differentiation of the air thermal conditions in SW part of Spitsbergen has been presented in this paper. Daily meteorological records of the Polish Polar Station of the Polish Academy of Sciences in Hornsund have been used for the period of 1978—1986. Distributions of basic thermal indices based on mean, maximum, minimum air temperatures and minimum temperature at a ground surface have been given. Annual patterns of the above elements of various occurrence probabilities have been also presented and thermal periods have been distinguished.