Hottest and Coldest Planets in the Solar System (Full Temperature Chart)
Solar System · Planet temperatures · Updated 2026-07-22
Venus is the hottest planet in the solar system, with a mean surface temperature of 464 C (867 F), and Neptune is the coldest planet at roughly -200 C (-328 F). Mercury orbits far closer to the Sun and still loses, because Venus is wrapped in 92 bars of carbon dioxide and Mercury has essentially no atmosphere at all.
The chart below gives mean, low and high temperatures for every planet in both Celsius and Fahrenheit, straight from the NASA Planetary Fact Sheet (NSSDC), plus the Moon and Pluto for comparison. It also flags the detail most temperature charts skip: for the gas and ice giants there is no solid surface, so the quoted number is measured at the 1-bar pressure level, not at a ground you could stand on.
Planet temperature chart: every planet, hottest to coldest
| Body | Mean temperature | Low | High | Where measured | Distance from Sun (10^6 km) | Atmospheric driver |
|---|---|---|---|---|---|---|
| **Venus** | 464 C / 867 F | ~464 C (night side barely drops) | ~464 C | Solid surface | 108.2 | 92 bar CO2, runaway greenhouse |
| **Mercury** | 167 C / 333 F | about -180 C / -290 F | about 430 C / 800 F | Solid surface | 57.9 | None. A trace exosphere holds no heat |
| **Earth** | 15 C / 59 F | -89.2 C / -128.6 F (Vostok, WMO record) | 56.7 C / 134.1 F (Furnace Creek, WMO record) | Solid surface | 149.6 | 1 bar N2/O2, about 34 K of greenhouse warming |
| **Moon** | -20 C / -4 F | -178 C / -289 F (equatorial night) | 117 C / 243 F (equatorial noon) | Solid surface | 149.6 (orbits Earth) | None |
| **Mars** | -65 C / -85 F | -89 C / -128 F (Viking 1 site) | -31 C / -24 F (Viking 1 site) | Solid surface | 228.0 | 0.01 bar CO2, negligible greenhouse |
| **Jupiter** | -110 C / -166 F | -161 C / -258 F at 0.1 bar | -108 C / -162 F at 1 bar | 1-bar level, no solid surface | 778.5 | H2/He, strong internal heat |
| **Saturn** | -140 C / -220 F | -189 C / -308 F at 0.1 bar | -139 C / -218 F at 1 bar | 1-bar level, no solid surface | 1432.0 | H2/He, strong internal heat |
| **Uranus** | -195 C / -319 F | -220 C / -364 F at 0.1 bar | -197 C / -323 F at 1 bar | 1-bar level, no solid surface | 2867.0 | H2/He/CH4, almost no internal heat |
| **Neptune** | -200 C / -328 F | -218 C / -360 F at 0.1 bar | -201 C / -330 F at 1 bar | 1-bar level, no solid surface | 4515.0 | H2/He/CH4, internal heat exceeds sunlight received |
| **Pluto** (dwarf planet) | -225 C / -373 F | -247 C / -413 F | -233 C / -387 F | Solid surface | 5906.4 | Thin nitrogen atmosphere, about 10 microbar |
Two rows need an asterisk. Earth's low and high are the World Meteorological Organization's verified surface records, not a daily range - NASA's diurnal figure for Earth is a gentler 10 C to 20 C. Mars's range is from the Viking 1 Lander site; polar winters are far colder, and NASA's Mars overview quotes a whole-planet span closer to -153 C to 20 C.
Why is Venus hotter than Mercury?
Because Venus keeps its heat and Mercury cannot. The clean way to see this is the black-body temperature - what a planet's surface would settle at from sunlight alone, with no atmosphere doing anything. NASA publishes it for every planet, and the gap between black-body and actual temperature is the greenhouse effect in one number.
- Mercury: black-body 439.6 K, actual mean 440 K. Greenhouse contribution: essentially zero. Mercury is exactly as hot as raw sunlight makes it.
- Earth: black-body 254.0 K, actual mean 288 K. Greenhouse contribution: +34 K, which is the difference between a frozen planet and a habitable one.
- Venus: black-body 226.6 K, actual mean 737 K. Greenhouse contribution: +510 K.
That is the whole answer. Venus receives 2,601 W/m2 of sunlight against Earth's 1,361, but its atmosphere is 96.5% carbon dioxide at 92 times Earth's surface pressure. Infrared radiation from the ground cannot escape to space, so heat accumulates until the planet reaches equilibrium at 737 K - a runaway greenhouse. Mercury, with a surface pressure around 5 x 10^-15 bar, radiates its heat straight back to space the moment the Sun sets.
Mercury's day-to-night swing is the real extreme
Mercury loses the hottest-planet title but holds the widest range: roughly -180 C at night to 430 C in the day, a swing of about 610 C on the same rock. A Mercury solar day lasts 4,222.6 hours, about 176 Earth days, so each hemisphere bakes for months then freezes for months with nothing to buffer the transition. Venus's diurnal range is essentially zero: its atmosphere is so dense and so well circulated that midnight is as hot as noon.
Why gas giants get a "1-bar" temperature
Jupiter, Saturn, Uranus and Neptune have no surface. Their hydrogen and helium envelopes simply get denser with depth until they turn fluid, so "surface temperature" is meaningless. Scientists solve this by picking a reference pressure - the 1-bar level, matching Earth's sea-level pressure - and quoting the temperature there. Deeper is hotter, fast: Jupiter's core is estimated in the tens of thousands of kelvin. Shallower is colder, which is why the low column for each giant above is its 0.1-bar value.
One cosmic fact a day, on every screen you own. StarQuest drops a new checked fact from its Solar System and Exoplanets categories every day, with widgets on your Home and Lock Screen and a fact on your Apple Watch. Start with the Essential collection, favorite the ones that stop you mid-scroll, and build your own galaxy. No ads, no login. Download StarQuest: Daily Cosmos Facts on the App Store.
Coldest planet vs coldest place in the solar system
These are two different questions and most pages conflate them. Neptune is the coldest planet, narrowly beating Uranus at the 1-bar level (-201 C against -197 C) despite being 1.6 billion km further out, because Uranus radiates almost no internal heat while Neptune emits more energy than it absorbs from the Sun. The coldest measured place is far closer to home: the permanently shadowed floors of polar craters on our own Moon. NASA's Lunar Reconnaissance Orbiter Diviner instrument has measured temperatures as low as about 25 to 26 K, roughly -248 C (-414 F), in craters like Hermite near the lunar north pole, where no sunlight has fallen in billions of years. That is colder than Pluto.
Keeping the numbers straight
Planet temperatures are among the most misquoted numbers online, mostly because sources silently mix mean, peak, 1-bar and black-body values. When you meet a figure, ask three things: mean or extreme, measured at what level, and from which source. StarQuest's Solar System category works the same way - one checked fact a day, so a number lands and sticks rather than ten washing past. Save the keepers to Favorites and they are there the next time someone insists Mercury is the hottest planet.
Frequently asked questions
What is the hottest planet in the solar system?
Venus, at a mean surface temperature of 464 C (867 F). Its atmosphere is 96.5% carbon dioxide at 92 times Earth's surface pressure, which traps outgoing infrared radiation and produces a runaway greenhouse effect worth about 510 K of extra warming.
Why is Venus hotter than Mercury if Mercury is closer to the Sun?
Mercury has no atmosphere, so it is exactly as hot as sunlight alone makes it - its black-body temperature of 439.6 K matches its actual mean of 440 K. Venus's thick CO2 atmosphere stops heat escaping, lifting it from a black-body 226.6 K to an actual 737 K.
What is the coldest planet in the solar system?
Neptune, at about -200 C (-328 F) mean, or -201 C at the 1-bar level. Uranus is close behind at -197 C at 1 bar and is colder in its upper atmosphere, at about -220 C at the 0.1-bar level. Pluto is colder still at around -225 C, but it is classified as a dwarf planet.
What is the average temperature of each planet?
Per the NASA Planetary Fact Sheet: Mercury 167 C, Venus 464 C, Earth 15 C, Mars -65 C, Jupiter -110 C, Saturn -140 C, Uranus -195 C, Neptune -200 C. For the four giants the value is measured at the 1-bar pressure level, since they have no solid surface.