EN
In the paper the frequency of days with maximum air temperature t max > 30°C and t max > 35°C, as well as of days with minimum temperature t min > l8°C and t min > 20°C, in Warsaw during the period 1947-2010 were investigated (Fig. 1, 2, Tab. 1). Numbers of mentioned days distinctly increased after 1900; the least numbers were in 1976-1980, the largest ones in 2006-2010 (table 1). In the 2010 the highest frequency of the warm nights (t min > l8°C - 22) and very warm (t min > 20°C - 6) occurred (Tab. 2). During the period 1947- 2010 the 35 heat waves were observed. In the 2010 were 4 heat waves, but the longest ones occurred in 1994 (10 days) and 1971 (9 days). Comparison of obtained results with the data from the first half of XX century shows that contemporary heats are not a new phenomenon in aur climate - the summers in 1921, 1939, 1943, 1944 and other years were also very hot.