It's autumn. Observe what has happened in nature and write a paragraph.

1, most plants will shed their leaves in autumn, which is an adaptation of plants to spend the cold season.

In autumn, the leaves of some plants change from green to yellow or red, which is related to the pigments contained in the leaves.

3. Is the air dry and windy? Small animals began to prepare for winter, and migrating animals began to migrate.

The direct sun moves to the south (for the northern hemisphere), so the days are getting shorter and shorter.

5. The climate is getting colder, the cold air is heading south, and the temperature is hot and cold frequently.

6. Autumn is also the harvest season. Orchards and fields have had a bumper harvest.

Extended data:

Autumn is the third season of the year, and the transition season from summer to winter is from September to165438+1October in the northern hemisphere, from March to May in the southern hemisphere, and from the autumnal equinox to the winter solstice in astronomy. Meteorologists study phenology according to the following criteria: after the summer heat, the five-day average temperature is below 22 degrees for autumn, and it ends below 10 degrees.

The most obvious change in the natural landscape is in the trees. Many fallen leaves will be cleaned up in the city, and many tourists will flock to the mountains to see the red leaves. There are six solar terms in autumn, namely beginning of autumn, Chushu, Bailu, Autumnal Equinox, Cold Dew and First Frost.

According to the standard of dividing seasons according to the average temperature, it must be that the average temperature for five days is below 22℃ to be considered as autumn. According to this standard, the Jianghuai area generally enters autumn in the middle and late September. After beginning of autumn, although the summer heat is hard to disappear for a while, there is still the afterglow of "autumn tiger", but the general trend is that the weather is getting colder and colder. The daily temperature range is gradually obvious, which is often very hot during the day and very cold at night.