Climate is commonly considered to be "the weather averaged over a long period of time, typically 30 years". The concept of "climate" includes the statistics of the weather—such as the degree of day-to-day or year-to-year variation."
Climate is variable across the globe; it is affected by landscape, relief, and activities (both human and physical). There are also microclimates. These are areas within a climatic region that can vary (e.g. top of hill, sunny side of hill, shaded side of hill, bottom of the hill, etc.). Climate is variable across time, including deep time.
It is important to note that weather is not the same as climate. Weather is the state of conditions at a certain point in time, as opposed to climate which covers a longer period of time. The different parts of the weather include: temperature, pressure, precipitation and humidity.
The science of monitoring and studying the atmosphere and predicting its weather and climate is called meteorology. People who study weather and climate are known as meteorologists.