The paper discusses the impact of urban planted areas: public parks and private planting around individual buildings, on various aspects of the quality of the urban environment. Specific issues discussed are: functions and impacts of urban planted areas; effect of plants on the climatic characteristics of an area; climatic impacts of private planted areas around buildings; experimental studies on the thermal effect of plants; public parks and the urban climate; range of the effect of urban parks; impact of green spaces on air pollution; planted areas as noise; social functions of urban parks; parks as social interaction areas between neighborhoods; and Climatic guidelines for parks design: Parks in hot, dry regions; Parks in hot, humid regions; and Parks in cold regions. Comment: This paper is based on a book by the author, published by the World Meteorological Organization (Givoni, 1989, Urban Design for Different Climates, WMO).