Weather describes short-term conditions of the atmosphere over a period of hours to weeks, while climate refers to the average atmospheric conditions over longer periods of time, typically decades or more. Weather involves day-to-day temperature, precipitation and other atmospheric conditions, whereas climate is the average weather usually described in terms of the mean and variability of these conditions over a period of years. Climate can change over time due to natural processes such as ocean circulation or human activities such as increasing greenhouse gas emissions.
