Climatic characteristics of autumnal equinox season

The climate characteristics of the autumn equinox season are that the temperature gradually decreases, the humidity in the sky increases, the air pressure changes little, the day and night are balanced, the precipitation decreases, and the air is crisp in autumn.

1, the temperature drops gradually.

In the autumn equinox, the northern hemisphere is in the transitional period of Xia Dong, and the angle of direct sunlight on the ground gradually decreases, the illumination weakens and the temperature gradually drops. Especially in the northern region, the temperature difference between day and night is obviously increased, which is colder during the day and colder at night.

2. The humidity in the sky increases.

The autumn equinox temperature drops, and the water vapor content in the air increases relatively, which leads to the increase of sky humidity. At this time, the sky is overcast and rainy weather often occurs. Especially in the south, the autumnal equinox season is the end of the rainy season, and the precipitation is relatively large.

3. The air pressure changes little.

In the autumn equinox, the atmospheric circulation changes obviously, the subtropical high in the south gradually weakens, while the cold air activity in the north increases, and the frequency of cold air heading south also increases. But generally speaking, the change of air pressure in the autumnal equinox is not particularly obvious, and the stability of the atmosphere is relatively good.

4, the length of day and night is balanced

At the autumnal equinox, the time between day and night becomes more balanced. The length of day and night is almost equal, each being 12 hour. At this time, the sun shines directly on the equator, and the sunshine time on the earth begins to decrease gradually.

5. Decreased precipitation

The precipitation in autumn equinox usually tends to decrease. But this season is still a relatively concentrated period of precipitation, especially in the north and south temperate regions. As the cold air moves south, there may be rainy weather.

6. Autumn is crisp

In the autumn equinox, the sun shines through the clouds. The sky is blue, the air is fresh and the temperature is suitable. In this weather, people feel relaxed and refreshed.

Baidu encyclopedia-autumnal equinox