The Short Version
This claim is a well-documented viral hoax, not a genuine official advisory. The Directorate General of Civil Defence does not have the institutional mandate to issue weather warnings — its role covers emergency preparedness for wars and disasters. Multiple authoritative sources, including the Press Information Bureau of India, the Kerala State Disaster Management Authority, and independent fact-checkers, have explicitly denied any such advisory was issued. This hoax follows a recurring pattern seen across multiple countries and years.