thermosphere
It is Exosphere
2,000°C
the thermosphere is the hottest all of the atmospheric layers.
A layer in the atmosphere in which temperature increases with altitude.
The hottest temperature typically occurs during the day when the sun is highest in the sky and the ground has had time to heat up. This is usually in the early to mid-afternoon. Elevation can influence temperature, with higher elevations generally experiencing cooler temperatures due to a decrease in air pressure and thinner atmosphere.
now well we don't really know what it is
The hottest temperatures in Earth's atmosphere occur in the thermosphere, which is found about 80 km (50 miles) above the surface. Temperatures in the thermosphere can reach up to 2,500 degrees Celsius (4,500 degrees Fahrenheit) due to absorption of highly energetic solar radiation.
Venus is the hottest planet. Its average surface temperature is 464 degrees Celsius. Its atmosphere has thick, pale, yellow clouds of carbon dioxide and sulfuric acid.
Venus is the hottest planet due to its out-of-control greenhouse atmosphere. Its temperature is between 752oF (400oC) - 932oF (500oC)
Within the Solar System, that would probably be Venus, with a temperature of almost 500 °C. Mercury is quite hot, too, but it has no atmosphere to speak of.
hottest temperature was 50.6 °C
The thermosphere