The hottest layer of the Earth’s atmosphere is the thermosphere. This layer is located above the mesosphere and extends from about 85 kilometers (53 miles) to around 600 kilometers (373 miles) above the Earth’s surface.
One of the interesting aspects of the thermosphere is that, although temperatures can soar to 2,500 degrees Celsius (4,500 degrees Fahrenheit) and even higher, the air is so thin that it wouldn’t actually feel hot to a human. The reason for the extreme temperatures is the absorption of highly energetic solar radiation by the sparse gas molecules present in this layer.
Because of the thermosphere’s altitude and low density, it also contains the ionosphere, which is critical for radio communication and is involved in auroras. The thermosphere plays a significant role in atmospheric dynamics and is vital for the interactions between the Earth’s atmosphere and space weather.