A microclimate is a local atmospheric zone with a climate differing from the surrounding area. It may be only a square meter, e.g. part of a garden, or square kilometers in size.
They may be created by:
- bodies of water which cool the air,
- dark colored hard surfaces such as brick, concrete, and asphalt, which absorb solar energy, become hot, and then heat the surrounding air - for example the urban heat island
- landforms which redirect, channel or slow down the prevailing wind.
- slope - South-facing slopes in the Northern Hemisphere and North-facing slopes in the Southern Hemisphere receive more direct sunlight and are thus warmer.
- walls and buildings, which intentionally or accidentally block sun and wind, and sometimes channel wind.
This is not only a critical factor to account for in sustainable design, but good design also improves the microclimate. Permaculture includes a focus on influencing the microclimate.
A walled garden is a clear example of a microclimate, protected from wind and potentially protected from frost.