What are the various climate changes in a certain area and within a certain period of time?

Weather tiānqì

[weather] The atmospheric conditions in a specific area in a relatively short period of time; meteorological conditions

The atmospheric conditions that are constantly changing, both within a certain period of time and the atmospheric state in space, which is also the continuous change of atmospheric state within a certain time interval. Therefore, it can be understood as a collective name for weather phenomena and weather processes. Weather phenomena refer to various natural phenomena that occur in the atmosphere, that is, the comprehensive expression of the spatial distribution of various meteorological elements (such as wind, clouds, fog, rain, snow, frost, thunder, hail, etc.) in the atmosphere at a certain instant. Weather process is the process of changes of weather phenomena in a certain area over time.

Weather is a general term for the atmospheric state (such as cold and warm, wind and rain, dryness and humidity, cloudy and sunny, etc.) and its changes in a certain area within a short period of time. Weather systems usually refer to atmospheric motion systems with typical characteristics such as high pressure, low pressure, high pressure ridges, and low pressure troughs that cause weather changes and distribution. Various weather systems have certain spatial and temporal scales, and systems of various scales are intertwined and interact with each other. The combination of many weather systems forms a large-scale weather situation and constitutes hemispheric or even global atmospheric circulation.