Clouds

Altocumulus clouds
Altostratus clouds
Cirrocumulus clouds over a forest
Cirrostratus clouds
Cirrus clouds over a winter landscape
Diagram of cloud types. High in the atmosphere are cirrocumulus and cirrus. In the middle of the atmosphere are altocumulus and altostratus. In the lower atmosphere are stratocumulus, stratus and cumulus. Cumulonimbus clouds can be found from near the ground up to above 50,000 feet.
Contrails
Cumulonimbus cloud
Cumulus clouds
Diagram of how clouds form
Kelvin-Helmholtz cloud
Lenticular clouds
Mammatus Clouds
Marine Stratocumulus Clouds
Nimbostratus clouds with a rainbow
A cloud floating in the middle of a museum room
Noctilucent clouds glowing on the horizon just after sunset
Polar Stratospheric Clouds
Stratocumulus clouds at sunset
Stratus clouds