Officially, Kraków has a temperate oceanic climate, denoted by Köppen classification as Cfb, best defined as a semicontinental climate. In older reference periods it was classified as a warm summer continental climate (Dfb). By classification of Wincenty Okołowicz, it has a warm temperate climate in the centre of continental Europe with the “fusion” of different features.
Due to its geographic location, the city may be under marine influence, sometimes Arctic influence, but without direct influence, giving the city variable meteorological conditions over short spaces of time.
Being towards Eastern Europe and a relatively considerable distance from the sea, Krakow has significant temperature differences according to the progress of different air masses, having four defined seasons of the year. Average temperatures in summer range from 18.6 to 20.4 °C (65 to 69 °F) and in winter from −0.6 to 0.8 °C (31 to 33 °F). The average annual temperature is 10.0 °C (50 °F). In summer temperatures often exceed 25 °C (77 °F), even reaching 30 °C (86 °F), while in winter temperatures drop to −5 °C (23 °F) at night and about 0 °C (32 °F) during the day. During very cold nights the temperature can drop to −15 °C (5 °F). The city lies near the Tatra Mountains, there are often occurrences of halny blowing (a foehn wind), causing temperatures to rise rapidly, and even in winter reach up to 20 °C (68 °F).
In relation to Warsaw, temperatures are very similar for most of the year, except that in the colder months southern Poland has a larger daily temperature range, more moderate winds, generally more rainy days and with greater chances of clear skies on average, especially in winter. The lower sun angle also allows for a larger growing season. In addition, for older data there was less sun than the capital of the country, about 30 minutes daily per year, but both have small differences in relative humidity and the direction of the winds is northeast.
The climate table below presents weather data from the years 2000–2012 although the official Köppen reference period was from 1981–2010 (therefore not being technically a climatological normal). According to ongoing measurements, the temperature has increased during these years as compared with the last series. This increase averages about 0.6 °C over all months. Warming is most pronounced during the winter months, with an increase of more than 1.0 °C in January.