Clouds, as we normally know them, are a weather phenomenon which can only occur in the troposphere which is only one small part of the whole atmosphere. Clouds can stretch from ground level to very high altitudes but only to the tropopause which marks the edge of the troposphere. This altitude varies from where you are situated on our planet and as well with the seasons of the year.

One popular way to group the different clouds is by dividing them by the altitude where they form and have their cloud base. The altitudes are not exactly defined but a typical grouping on northern latitudes (Europe, North America) is shown here.

Low clouds - Ground to 8000 ft or 2500 m

Medium high clouds - 8000 ft or 2500 m to 20000 ft or 6000 m

High clouds - Above 20000 ft or 6000 m

This is only a rough grouping considering that the tropopause can vary from as low as 8000 m over the poles up to as high as 18000 m over the equator.

A fourth group which could be added is clouds with large vertical extension. Here these clouds are incorporated in the group low clouds with the exception of nimbostratus which is a medium high cloud.

On this site you will also find the group other phenomena where you can find precipitation, rainbows and other light effects in the sky.

For images and further details, start exploring by clicking a group below or on the navigator to the left.