The course and changes of air temperature at peak Moussala for the period 1933-2007 are revealed in the paper. Subject of investigation are both average annual and monthly temperatures. Station data are homogeneous for the period of research. Only the values for 1996 are recovered based on data from Cherni Vruh station using the method of differences. Other methods employed in this paper are trend, autocorrelation and spectral analyses. The main conclusion is that there is statistically significant atmosphere air warming at peak Moussala, which corresponds to data from other parts of the world. This trend is especially visible during the last 25-30 years. There are no cycles in average annual temperatures. The main contributors to the warming at peak Moussala are months of January and June. There are some significant cycles in average monthly temperatures of March, August and December. There are also some significant cycles in monthly air temperature deviations with periods of 2.1 months, 100 months and 288 months.