The urban atmosphere contains lots of pollution in the form of solid particles. Together with the strongly altered mostly artificial urban surface, these significantly change the radiation balance in a city compared to non-urban areas. The radiation balance and the heat balance are closely correlated. The heat balance of an urban area is complex due to the large number of buildings and includes heat exchange through conduction by the ground, streets and walls as well as the heat from the combustion of fossil fuels. In a city, the water balance is also controlled by these same elements, but their proportions are significantly different. In urban areas, the amount of rainfall is higher than in non-urban areas.
The urban climate may have a negative effect on people primarily through air pollution and noise. Urban air pollution from vehicles is particularly harmful, it can cause acid rain and can reduce the amount of solar radiation reaching the ground. Increasing the amount of parks can help reduce the negative impacts of the urban climate on humans.