| Peak | Body | Outlook |
|---|---|---|
| Olympus Mons | Mars | Thin carbon-dioxide air (about 600 Pa at the datum, far less at these summits), daytime highs near −20°F that plunge below −150°F at night, and planet-girdling dust storms. |
| Rheasilvia | Vesta (asteroid) | Airless and frigid (about −190°F in sunlight). |
| Equatorial Ridge of Iapetus | Iapetus (moon of Saturn) | Airless, about −225°F, and famously two-faced — one hemisphere is coal-black, the other bright ice. |
| Boösaule Montes | Io (moon of Jupiter) | No breathable air, sulfur-dioxide frost, 300 km-high volcanic plumes, and a lethal bath of Jovian radiation. |
| Ascraeus Mons | Mars | Thin carbon-dioxide air (about 600 Pa at the datum, far less at these summits), daytime highs near −20°F that plunge below −150°F at night, and planet-girdling dust storms. |
| Ionian Mons | Io (moon of Jupiter) | No breathable air, sulfur-dioxide frost, 300 km-high volcanic plumes, and a lethal bath of Jovian radiation. |
| Elysium Mons | Mars | Thin carbon-dioxide air (about 600 Pa at the datum, far less at these summits), daytime highs near −20°F that plunge below −150°F at night, and planet-girdling dust storms. |
| Arsia Mons | Mars | Thin carbon-dioxide air (about 600 Pa at the datum, far less at these summits), daytime highs near −20°F that plunge below −150°F at night, and planet-girdling dust storms. |
| Maxwell Montes | Venus | The worst weather anywhere: a ~465°C surface, 90+ atmospheres of crushing carbon dioxide, and clouds of sulfuric acid. |
| Euboea Montes | Io (moon of Jupiter) | No breathable air, sulfur-dioxide frost, 300 km-high volcanic plumes, and a lethal bath of Jovian radiation. |
| Mauna Kea | Earth | Actual weather! Wind, snow, and breathable air (less of it the higher you go). |
| Mauna Loa | Earth | Actual weather! Wind, snow, and breathable air (less of it the higher you go). |
| Mount Everest | Earth | Actual weather! Wind, snow, and breathable air (less of it the higher you go). |
Global and regional dust storms on Mars can blot out a summit for weeks. Current status: regional activity on the Tharsis rise.
When a body passes behind the Sun, relay-sat contact drops for days to weeks. Plan your summit window around it.