Typically when we think of seasons we think of those we experience on Earth, lasting around 3 months, and having unique characteristics as far as temperature and weather go. Things are a bit different on Uranus, due to a huge impact that the planet experienced billions of years ago. This impact knocked the axis of the planet on its side in its plane of orbit around the sun, and now the seasons on Uranus are quite extreme. With an orbit of 84 Earth years, each hemisphere (North and South) of Uranus will spend 1/4 of its orbit, or 21 straight years bathed in sunlight, followed up later by 21 years of total darkness. The image below shows the orbit of Uranus around the Sun, with its rotational axis labeled.
This unique tilt creates some odd weather patterns. In 1986 the Voyager 2 probe took photos of Uranus during one of the planet’s 21-year long solstices. The image below, taken from the satellite, shows a peaceful image of Uranus, with gentle uniform coloring throughout.
18 years later, in 2004, images of Uranus were taken through various telescopes, and a much different picture of the planet appeared. The surface of the planet was covered in storms and the weather seemed erratic and harsh. The change from 21 years of sunlight, or 21 years without, to what we think of as a normal day-night cycle (although Uranus’ is only about 17 hours) proves to be chaotic for Uranus’ atmosphere.