Is GC Leong or only NCERTs enough for Geography in UPSC?

For a solid Geography strategy, NCERTs (Class 6–12) are absolutely mandatory, but G.C. Leong’s Certificate Physical and Human Geography is a highly recommended supplement for specific sections.
NCERTs serve as your primary foundation. The Class 11 and 12 books are particularly vital, covering both physical and human geography with government-verified data and the exact terminology needed for Mains.
For many aspirants, these textbooks provide enough information to tackle a significant portion of the Prelims. However, they can occasionally lack the detailed analysis required for complex physical processes.
G.C. Leong fills these conceptual gaps. It is particularly famous for its second half, which provides a much more thorough explanation of global climatic regions—like the Mediterranean or Steppe climates—than the NCERTs do. Its clear diagrams are also excellent for learning how to illustrate answers in the Mains. That said, the book does not cover Indian Geography at all, so it cannot be your only resource.
The most effective approach is to master the NCERTs first to understand the broad syllabus and Indian context. Then, read G.C. Leong selectively to strengthen your understanding of physical geography and climate zones.
Finally, always supplement both with a reliable Atlas for mapping and current affairs for topics like climate change and natural disasters. This combined method ensures you have the foundational facts from NCERTs and the analytical depth from Leong.