The weather on Mercury is characterized by extreme temperatures and a lack of atmosphere. Mercury is the closest planet to the Sun, so it experiences extreme heat during the day and extreme cold at night. During the day, temperatures can reach up to 450 degrees Celsius (842 degrees Fahrenheit), making it hot enough to melt lead. At night, temperatures can drop to as low as -180 degrees Celsius (-292 degrees Fahrenheit).

Mercury has a very thin atmosphere, composed mostly of helium and oxygen. The atmosphere is so thin that it does not provide any significant insulation, so the temperature can change rapidly. There is no liquid water on Mercury, and the surface is mostly covered in rocks and dust.

The weather on Mercury is also affected by the planet's rotation. Mercury rotates very slowly, taking about 59 Earth days to complete one rotation. This means that the planet experiences long days and nights. During the day, the Sun shines directly on Mercury, heating the surface. At night, the planet cools down quickly, as there is no atmosphere to insulate it.

The weather on Mercury is very different from the weather on Earth. The extreme temperatures and lack of atmosphere make Mercury a very hostile planet for life.