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The paper focuses on the frequency, annual pattern and long-term variability of thermal specific days in Warsaw during the period 1951 - 2010. The following were distinguished : days with frost ( tmax ≥ 0.0 °C, tmin < 0.0 °C ), cold days ( tmax -0.1 - -10.0°C ), very cold days ( tmax - 10.1- - 20.0 °C ), extremely cold days ( tmax < -20.0°C ), hot days ( tmax 25.1-30.0 °C ), very hot days ( tmax 30.1-35.0 °C ) and extremely hot days ( tmax > 35.0 °C ) as well as warm nights ( tmin 15.1 - 18.0 °C ), very warm nights ( tmin 18.1 - 20.0 °C ) and tropical nights ( tmin > 20.0 °C ). The following average numbers of days/nights per year were found during the period 1951 - 2010 : 109 days with tmin < 0.0°C, including 37 days with tmax < 0.0°C, 38 days with tmax > 25°C, and 21 nights with tmin > 15.0 °C. The minimum temperature ranged from -30.7 °C to 21.8 °C and the maximum temperature from -20.4 °C to 36.4 °C. The number of days with tmax ≥ 0.0 °C and tmin < 0.0 °C dropped by 1.8 day/10 years, days with tmax < 0.0 °C also by 1.8 day / 10 years; the number of days with tmax > 25.0 °C rose by 2.2 day / 10 years, while the number of days with tmin > 15.0 °C rose by 2.4 day / 10 years. The results are based the on data collected at the Okęcie airport station, which is located outside the town and therefore they are not representative of the Warsaw urban area, but rather of the eastern part of the Warsaw basin. [ABSTRACT FROM AUTHOR]