From Lexicanum

Desert worlds are desolate planets with no bodies of water and with completely desert terrains. Since "desert world" only refers to the planet's terrain, most human-populated desert worlds fall into a technical Imperial class, such as civilized world, feral world or death world. Inhabited desert worlds often produce tough people who know how to survive in the most barren of environments.

Generally, the planets are desert worlds when they are colonised, but in some extreme cases such as virus bombing, a formerly habitable planet had its ecosystem completely destroyed, leading to planetwide desertification. This was the case on Tallarn when it was bombarded by the Iron Warriors.

Notable desert worlds

Planet name	Segmentum	Sector	Subsector	System	Population
Masali	Ultima Segmentum	Unknown	Unknown	Unknown	Unknown
Quintarn	Ultima Segmentum	Unknown	Unknown	Unknown	Unknown
Tallarn	Segmentum Tempestus	Unknown	Unknown	Tallarn System	Unknown
Tarentus	Ultima Segmentum	Unknown	Unknown	Unknown	Unknown
Thoth	Segmentum Pacificus	Unknown	Unknown	Unknown	Unknown

Tarentus, Masali and Quintarn are each part of the Ultramarines empire of Ultramar and are each used as food producing worlds. They have vast bio-domes covering much of the surface along with several water traps, catching and storing as much water as the barren land can give them.¹

Worlds of the Galaxy

Imperium	Adeptus Astartes Homeworld • Agri World • Cardinal World • Civilised World • Dead World • Death World • Desert World • Feral World • Feudal World • Forge World • Hive World • Ice World • Industrial World • Jungle World • Knight World • Mining World • Ocean World • Paradise World • Penal World • Research Station • Shrine World
Xeno	Xenos World • Daemon World • Exodite World • Tomb World • Maiden World • Crone World • Ork World • Tau Empire • Craftworld

Sources

• ¹:Codex: Ultramarines (2nd Edition)