Urbanisation and building design significantly affect local humidity levels. The reduction of vegetation in urban areas leads to decreased evapotranspiration – the process by which plants release water vapour into the air, which is a natural humidifying process. In contrast, urban surfaces like concrete and asphalt do not provide this benefit, leading to lower humidity levels in cities. Moreover, the design of buildings and the urban layout can influence air circulation, often leading to areas of low humidity. For instance, densely packed high-rise buildings can restrict airflow, preventing the dispersal of humidity. These changes in humidity can impact local climate, human comfort, and the health of urban ecosystems. Therefore, incorporating features such as green roofs, urban forests, and water features in urban design is essential for maintaining balanced humidity levels in urban environments.

Urban precipitation patterns often differ significantly from those in rural areas, a phenomenon primarily attributed to the Urban Heat Island effect and increased air pollution. Urban areas typically experience higher temperatures, which can lead to increased evaporation and more intense convection currents. This often results in heavier and more frequent rainfall in cities compared to their rural counterparts. Additionally, air pollution in urban areas provides additional nuclei for cloud formation, potentially leading to changes in the nature and timing of precipitation. These altered precipitation patterns can have several consequences, including increased risk of urban flooding due to the concentration of impermeable surfaces, challenges in water management, and impacts on urban ecosystems. Effective urban planning, including the creation of permeable surfaces and adequate drainage systems, is crucial in managing these consequences and ensuring sustainable urban development.

Urban climatic effects can indeed have an impact on global climate change, primarily through the amplification of certain processes that contribute to global warming. The Urban Heat Island effect, for instance, contributes to increased energy consumption for cooling in cities, leading to higher emissions of greenhouse gases if the energy is produced from fossil fuels. Additionally, the alteration of natural landscapes in urban areas affects carbon sequestration capabilities; for example, the replacement of vegetation with concrete reduces the amount of carbon dioxide that can be absorbed from the atmosphere. Furthermore, changes in local weather patterns, like altered precipitation and increased air pollution, can have broader climatic implications. While urban areas cover a relatively small fraction of the Earth's surface, their intensified activities and climatic impacts can contribute significantly to global climate change, underscoring the need for sustainable urban planning and development strategies.

Green spaces in urban areas play a crucial role in modifying wind patterns. Trees and vegetation act as natural windbreakers, reducing wind speed and turbulence. This is particularly important in urban settings where the construction of high-rise buildings can lead to the formation of wind tunnels at street level, making conditions uncomfortable and potentially hazardous. Green spaces disrupt these wind tunnels, creating a more stable and gentle wind flow. Moreover, the strategic placement of trees and vegetation can channel winds in a way that enhances natural ventilation, improving air quality and reducing the reliance on mechanical cooling systems. Additionally, urban parks and green belts can serve as buffer zones, absorbing and dissipating wind energy, thereby moderating local climate conditions and contributing to a more comfortable urban environment.

The design of urban surfaces has a significant impact on the Urban Heat Island (UHI) effect. Surfaces such as concrete and asphalt absorb and retain heat more efficiently than natural landscapes, leading to higher temperatures in urban areas. The colour and material of these surfaces play a crucial role; darker colours absorb more solar radiation, exacerbating the UHI effect. Conversely, lighter-coloured surfaces reflect more sunlight, helping to reduce heat absorption. Additionally, the use of permeable materials allows for better water absorption and evaporation, which can help cool the air. Urban planning strategies, therefore, often include the use of high-albedo materials, green roofs, and permeable pavements to mitigate the UHI effect. These modifications not only reduce surface temperatures but also contribute to overall urban sustainability by improving stormwater management and increasing urban greenery.