Highest temperature recorded on Saturn

The highest temperature recorded in the atmosphere of Saturn is 151 Kelvin (-122 C; -188 F), measured in the stratosphere over the planet's south pole. The readings were taken by astronomers working at the Keck Observatory in Hawaii, USA, and published in the journal Science on 3 February 2005.

The sunlight that reaches a planet’s poles has to travel through the atmosphere at a shallow angle, losing much of its energy on the way. On every other planet that has been studied, the poles are therefore the coldest places. It is not clear why Saturn’s poles are warmer, but it seems to be related to the massive polar vortex weather systems that are established over each.

In 2008, data collected by the Cassini probe revealed that there was a similar warm spot centred over the planet's north pole. Both the northern and southern warm spots are extremely localized, with the temperature rising rapidly at latitudes greater than 70 degrees in the north and south. The northern hot spot was found to be cooler than the southern one, because it has been winter at the northern hemisphere on Saturn since 1995 (Saturn's orbital period – its "year" – is 29.5 times longer than Earth's), but it was still significantly warmer than the atmosphere at lower latitudes.