Why is it so hot in summer?

When the temperature is very high in summer, some water on the ground turns into steam and rises continuously. The steam near the ground is heated by the ground heated by the sun, and there is a great difference between hot and cold, thus forming a strong air convection and developing into a cumulonimbus cloud that can produce hail. Rising water vapor condenses in the air to form ice cubes. Because the airflow in the cloud is very strong, the hail cube in the cloud can be dragged to fuse with the small water droplets and snowflakes in the updraft to form ice cubes with alternating layers of transparency and opacity. When these spherical, conical and irregular ice cubes increase to a certain extent, when the rising airflow can't drag them, they fall to the ground to form hail.

There is hail in summer because: in midsummer, the ground temperature is as high as 30 degrees Celsius, but with the increase of height, the temperature of the rising air becomes lower and lower. The temperature at the bottom of the cloud is only 20 degrees Celsius, and the place about 4 thousand kilometers from the ground is only below 0 degrees. Under the strong air convection, the cumulonimbus cloud can develop upward to more than 10 km, where the low temperature is enough to provide conditions for the formation of hail.