Thermal Atlas of the Solar System
Uranus
Temperature at 100 mbar (Voyager 2)
Temperature map of Uranus's upper atmosphere from Voyager 2: the coldest planet, with a warm equator and poles and cool mid-latitudes.
About Uranus
Uranus has no surface. This is the temperature near the top of its lower atmosphere, where the pressure is a tenth of Earth's, measured by Voyager 2 when it flew past in January 1986. It is the coldest planet: about −221 °C here.
Uranus is tipped on its side (98°), so each pole gets about 42 years of sunlight and then 42 years of darkness. In 1986 the south pole pointed almost at the Sun. Yet the temperatures have barely changed: telescope images from 2018, in northern spring, match Voyager's to within 0.3 °C at most latitudes.
The equator is about 2 °C warmer than the mid-latitudes, and the poles about 1 °C. Air is thought to rise and cool at mid-latitudes and to sink and warm over the equator and poles. Voyager's measurements were averaged around each latitude, so the map shows bands only.