Jupiter, the largest planet in our solar system, is a massive gas giant composed predominantly of hydrogen and helium. The concept of a single “temperature” does not apply because the planet lacks a solid surface. Its structure transitions smoothly from a cold, gaseous atmosphere to a hot, fluid interior, resulting in dramatic temperature changes from its freezing-cold cloud tops to its super-heated core.
Temperature Profile of the Upper Atmosphere
The visible atmosphere of Jupiter is the coldest region of the planet, with temperatures primarily dictated by solar radiation and local atmospheric pressure. The cloud tops, where the distinct white zones and darker belts form, have temperatures around 150 Kelvin, or approximately -123 degrees Celsius (-190 degrees Fahrenheit). These clouds are composed of ammonia ice crystals that condense at this thermal level.
As one descends deeper into the atmosphere, the temperature begins to rise due to increasing pressure. At the 1-bar pressure level (equivalent to Earth’s sea-level pressure), the temperature is approximately 165 Kelvin, or -108 degrees Celsius (-163 degrees Fahrenheit). Deeper still, where water clouds are thought to condense, the temperature approaches 270 Kelvin, which is near the freezing point of water.
Moving upward from the visible clouds, the temperature decreases through the troposphere until it reaches its minimum point at the tropopause. This boundary layer sits at a pressure of about 0.1 bar and measures a frigid 110 Kelvin, or -163 degrees Celsius. Above the tropopause, in the stratosphere, temperature begins to climb again due to the absorption of solar ultraviolet radiation by hydrocarbons. This heating causes temperatures to rise to about 200 Kelvin at the transition into the thermosphere.
Jupiter’s Powerful Internal Heat Engine
Unlike terrestrial planets, Jupiter possesses a potent internal heat source. Observational data confirms that Jupiter radiates nearly twice the amount of thermal energy that it absorbs from the Sun. This excess energy is the result of an ongoing process known as the Kelvin-Helmholtz mechanism.
This mechanism is driven by the slow, continuous gravitational contraction of the planet. As Jupiter’s immense gravity compresses its interior, gravitational potential energy is converted directly into thermal energy. This heat travels outward, ensuring that the deeper atmospheric layers are much warmer than they would be from solar heating alone.
This internal heat drives the atmospheric circulation and weather systems observed on the planet. The gravitational contraction is subtle but constant, causing the planet to shrink at an estimated rate of about one millimeter per year. This slow contraction has maintained an interior temperature far greater than any external energy source could provide.
The outward flow of this internally generated heat contributes to the uniform temperature across the planet’s equatorial and polar regions in the troposphere. This thermal balancing effect is a direct result of deep convection driven by the internal heat, which acts like a thermostat for the lower atmosphere. The Kelvin-Helmholtz mechanism distinguishes Jupiter’s thermal evolution from that of smaller, colder worlds.
Extreme Temperatures of the Deep Interior
The internal heat engine drives temperatures in Jupiter’s deep interior, creating conditions of extreme heat and pressure. Beneath the gaseous and fluid molecular hydrogen layers, the planet’s internal pressure compresses the hydrogen into a state known as liquid metallic hydrogen. This layer is electrically conductive and is the source of Jupiter’s powerful magnetic field.
At the base of the liquid metallic hydrogen layer, the temperature continues to climb, reaching tens of thousands of degrees. Estimates for the temperature near the planet’s core—a dense region likely composed of rock, metal, and ices—are modeled to be around 24,000 degrees Celsius (43,000 degrees Fahrenheit). Other models suggest temperatures may range higher, possibly up to 35,000 degrees Celsius.
These high temperatures are a direct consequence of the overwhelming pressure, which can reach millions of times the atmospheric pressure found on Earth. This immense pressure prevents the material from expanding and cooling, sustaining the thermal environment. The core temperature is so high that it rivals the surface temperature of the Sun, which is approximately 5,500 degrees Celsius.
The deep interior of Jupiter presents a stunning thermal contrast with the planet’s atmosphere, moving from a frigid 110 Kelvin at the tropopause to tens of thousands of degrees at the center. This extreme temperature gradient, maintained by gravity and the planet’s own ongoing contraction, illustrates the vast thermal complexity hidden beneath the swirling clouds.