What phenomenon knows it's going to rain?

Before the storm, the outside air pressure decreased, the weather was sultry, and the transpiration of plants increased. The bulbs of yuhua district store nutrients and produce a lot of hormones to promote flowering, so a large number of flowers will be produced.

2. Sweden's "warm grass"

There is a kind of "warm grass" in Sweden, which can measure the temperature like a thermometer: when the temperature is above 20℃, the leaves protrude obliquely upward; At 15℃, the blade moves down slowly until it is parallel to the ground; At 10℃, the blades extend obliquely downward.

3. The "shyness" of mimosa

Mimosa leaves shrink slowly after being touched, or open slightly, which indicates the future of wind and rain; It closes quickly after being touched, but it takes a long time to recover, which indicates that the future will be sunny.

4. Spiders weave webs

As the saying goes, "spiders weave webs, and after the rain, it clears up." On rainy days, if the air pressure increases, the humidity decreases and insects fly high, spiders will open their nets to prey on insects, which indicates that the weather will clear up. On the contrary, the spider closes its net, which indicates that it will rain.

Bees don't leave their nests.

Before it rains, bees' wings are easily wetted by tiny water drops, which makes them gain weight and make it difficult to fly, so they have to stay in the hive.