This graphic shows cloud heights at different latitudes on the Earth. For example, a high cloud like a cirrus cloud would be found at a lower height in the sky at the poles than at the equator (which is in the tropics). Courtesy of Lisa Gardiner/UCAR

Different types of clouds can be found at different heights in the sky. In addition to cloud type determining its height, latitude plays a role in how high a cloud is in the sky. Most clouds we see, including clouds that are related to weather, are located in a layer of the atmosphere called the troposphere.

The troposphere has different depths at different places around the Earth. The troposphere is deeper, or higher, near the equator, and it is thinner near the poles. This is because the air is warmer near the equator than at the poles. The Sun heats the Earth mostly at and near the equator, and this warm air rises and causes the troposphere to be deeper above this part of the planet. At and near the poles, the air is cooler and sinks, so the troposphere is thinner above this part of the planet. Because of this, high clouds in the tropics have a higher base and a higher top than high clouds in the mid-latitudes or high clouds in the tropics.