When will it get cold?

Generally, at the end of September1early October, the weather begins to cool down slowly. Weather refers to the specific state of the near-surface atmosphere in a short time. Weather phenomenon refers to various natural phenomena in the atmosphere, that is, the comprehensive expression of the spatial distribution of various meteorological elements in the atmosphere (such as temperature, pressure, humidity, lightning, wind, clouds, fog, rain, snow, frost, lightning, hail, haze, etc.). ) in an instant.

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1. The weather process is the change process of weather phenomena with time in a certain area. All kinds of weather systems have certain time and space scales, and they are intertwined and influence each other. The combination of many weather systems constitutes a large-scale weather situation and hemispheric and even global atmospheric circulation. The weather system is always in the process of rebirth, development and extinction, and there are corresponding weather phenomena in different development stages.

2. Weather refers to the ever-changing atmospheric state, which is not only the atmospheric state in a certain time and space, but also the continuous change of atmospheric state in a certain time interval. So it can be understood as a general term for weather phenomena and weather processes. Weather phenomenon refers to various natural phenomena in the atmosphere, that is, the comprehensive expression of the spatial distribution of various meteorological elements in the atmosphere (such as temperature, pressure, humidity, wind, clouds, fog, rain, snow, frost, lightning, hail, etc.). ) in an instant. The weather process is the change process of weather phenomena with time in a certain area.

3. The weather system is always in the process of rebirth, development and extinction, and there are corresponding weather phenomena in different development stages. Therefore, the weather and weather changes in a region are related to the weather system and its development stage, and are the comprehensive results of atmospheric dynamic and thermal processes.