What are the natural phenomena before it rains?

Common natural phenomena before rain include cloudy days, dark skies and falling temperatures.

1. Pressure drop

Before it rains, the air pressure usually drops, because the increase of water vapor makes the ground air pressure drop. Low air pressure can make people feel uncomfortable and dizzy.

2. Cloudy/gloomy sky

When water vapor evaporates and sublimates to a certain height to form a cloud, it will block the sun, causing the sky to become dim or overcast. This is usually a sign before it rains.

3. Temperature difference

As the weather changes, the water vapor increases and the temperature tends to decrease. At this time, people may feel cold or wet.

Expand knowledge:

In addition to the natural phenomena mentioned above, there may be other signs before it rains, such as increased wind, increased humidity and increased static electricity. All these signs may mean rain.

Atmospheric pressure and temperature drop will affect the emotional state of bipolar patients.

In some areas, it is also believed that the behavior of certain animals or insects can predict rainfall, such as cobwebs and swarms of locusts. However, these ideas have no scientific basis and are misleading.

According to meteorological research, when three factors, namely low air pressure, temperature decrease and humidity increase, appear at the same time, it often rains.

Rain is a natural landscape, but the water on the earth is turned into steam and evaporated into the air after being irradiated by sunlight. Water vapor condenses into small water droplets when it meets cold air at high altitude. These water droplets are very small, with a diameter of only 0.0 1~0.02 mm and a maximum of only 0.2 mm. ..

They are small and light. They are held up by the updraft in the air. It is these small water droplets that gather in the air to form clouds. These small water droplets will become raindrops and fall to the ground, and the volume will increase by about 1 10,000 times.

When it rains, how do these small water droplets increase their volume to more than 1 10,000 times? Mainly by two means: one is condensation, and the other is the increase of cloud droplet collision. In the initial stage of raindrop formation, cloud droplets mainly condense and condense themselves by constantly absorbing water vapor around the cloud.