£ódŸ is the second largest city in Poland as far as the number of its inhabitants (800 thousands) is concerned. The overall area of its building development amounts to more than 200 square kilometers, but the very built over area covers only 80 square kilometers. Population density in central areas of the city reaches more than 15 thousands inhabitants per one square kilometer. Height differences of the built over area are not significant (not exceed 10 meters per one square kilometer). Height of buildings and the urban building development content are the most important factors which influence the local climate of the city. The intensity of the urban heat island and all the secondary effects arising from its existence in urban conditions of £ódŸ depend primarily on the building development. This paper will present the results of map analysis of the city area. The aim of the analysis was to determine the percent fraction of artificial areas including roofs, pavements and asphalt, green areas divided into low greens (lawns, waste lands, fields) and high greens (trees in parks and forests) etc. The net of squares, whose sides equaled 0.5 kilometer, was the basic card field for calculations, whereas the plans' scale was 1:2000 and 1:1000. Additionally, other indexes which characterize the urban building development were also used. These included, for instance, buildings' cubature index and roughness parameter after Lettau's formula (frontal area index) for directions of flow N-S and W-E. The conducted analysis has shown that the area of £ódŸ, as far as its size and structure of the building development are concerned, can be treated as a typical proof ground of the European city's climate.

Keywords: urban surface, urban climate