Our closest neighbor Venus is only slightly smaller than Earth and maybe even had liquid water on its surface at one point in its distant past. Today it’s a scorching 860°F on the surface due to a runaway greenhouse effect, with about 98% of its atmosphere consisting of CO2. Because of the heavier greenhouse gases making up its atmosphere, Venus also has a surface pressure equivalent to 3,000 feet below the ocean on Earth. Even a relatively light wind on Venus would have a crushing force to it thanks to this pressure; I think I’d pass on trying to observe the weather here!

Mars has become a popular topic with recently planned missions and talk of manned habitation on the planet, meaning weather forecasting on Mars is within the realm of possibility! Mars actually sees changes in the seasons due to it having a similar tilt to that of Earth. In general, it is much colder due to its extremely thin atmosphere and further distance from the Sun. Temperatures range from roughly -225°F to 95°F; and so a very warm day on Mars is still warmer than Mount Washington’s record of 72°F. Mars doesn’t have precipitation of any kind due to there not being any significant water vapor in the air, but it does have frequent dust storms, some of which can grow large enough to cover the entire planet.

We certainly see some impressive weather extremes here on the summit of Mount Washington, but Neptune’s weather is on a completely different level than that of Earth. Neptune is the furthest planet from the sun, (sorry Pluto) but it actually has an extremely dynamic and complex atmosphere. Neptune produces 2.6 times more heat than it receives from the Sun, and the mechanism for this heat production still isn’t fully understood.

 Neptune viewed from the Voyager II mission as it passed by in 1989. Note the Great Dark Spot!

Temperatures near Neptune’s solid core may be as high as 9,000°F, with readings in the troposphere, where most of the weather occurs, falling off to an incredibly cold -360°F. This temperature difference fuels massive storms like the Great Dark Spot, similar to the Great Red Spot on Jupiter. Winds during the 1989 Voyager II flyby of the planet were remotely clocked at 1,300 mph, or almost twice the speed of sound on Earth! These are the fastest winds recorded in our Solar System. Taking a look around at the weather of our neighboring planets definitely helps to put it into perspective how harsh conditions can be across the vastness of space, and when it comes to Earth’s weather there’s no place like home!