EnvironmentalVisualEnhancements - Clouds and City Lights
EnvironmentalVisualEnhancements (a.k.a. EVE) is a mod for KSP that adds clouds and city lights. It is highly configurable and a number of other mods provide improved clouds not just for the stock planets, but for other planets provided by other mods.
Go HERE for E.V.E. for later versions of KSP
The mod works on KSP 1.8, and olde