Summary:

Results of air temperature measurements in the 1957-2014 multi-annual period were analysed in the paper. The data originated from Jelcz-Laskowice locality situated in the south-western part of Poland, at the flat part of the Lower Silesia, on Silesian Lowlands. Average annual and monthly air temperatures and the number of days of thermal seasons duration were analysed. Trends of changes were set and extreme values of average monthly air temperatures were analysed. Mean annual air temperatures in the studied multi-annual period revealed a tendency to increase. Average monthly extreme values of the analysed factor revealed a similar direction of changes; however, more apparent changes occurred for the maximum values. Over the analysed period, average monthly air temperatures revealed a tendency to increase. The most serious changes occurred in July, slightly lesser in August, May and April. The number of days in the years 1957-2014 in the interval limited by the air temperature threshold values: 0oC, 5oC and 15oC was greatly diversified. Analysed results had a clear growing tendency for the summer, slightly lower for the spring, but evidently declining for the autumn.