This retreating cumulonimbus cloud, or thundercloud, is somewhat unusual as it contains the rare mammatus cloud on the near end, while simultaneously producing falling rain on the far end. Image © Alan Dyer (The Amazing Sky)
Taken in mid-June in southern Alberta, Canada, the cloud is moving to the east, into the distance, as the sun sets in the west, behind the camera.
In the above image, graphic sunset colors cross the sky to give the already photogenic cloud striking orange and pink hues. A darkening blue sky covers the background. Further in the distance, a rising, waxing, gibbous moon is visible on the far right.