In South Africa, the country with the largest number of people living with HIV, and the twelfth-highest tuberculosis incidence rate, the impact of climate change and extreme weather on health systems is a major threat. Extreme events increase the need for health services, damage health systems, reduce the health workforce, disrupt supply chains and supporting services, and interrupt disease prevention, testing and treatment regimes. This jeopardizes the health, and increases the vulnerabilities, of people living with HIV and/or tuberculosis. In this policy analysis we examined how extreme weather events are reflected in HIV/tuberculosis policies, and conversely, how these diseases are considered in climate adaptation and disaster risk management. We analysed 85 global, regional and South African policy documents on HIV, tuberculosis, climate(-health) and disaster management. We conducted semi-structured interviews with six key experts involved in guideline development. The resulting transcripts were analysed these through a hybrid inductive and deductive thematic approach, by generating an exhaustive list of codes and mapping these to Walt and Gilson’s policy triangle (actors, context, content, process). We found that policy integration between HIV/tuberculosis and climate is currently limited to high-level recognition, with minimal translation into operational content. Extreme weather was barely mentioned in HIV/tuberculosis guidelines, while HIV/tuberculosis appeared mostly as contextual background in climate policies. Interviews with HIV/tuberculosis experts highlighted gaps in operational guidance, disaster preparedness, early warning systems, and inter-sectoral coordination. Experts identified options for crisis-proofing HIV/tuberculosis services, including improved disaster response strategies, differentiated service delivery, multi-month dispensing, telemedicine, electronic health records, better communication, coordination, training and integration with disaster management. They suggested potential entry points for new policy content. Integrating climate and disaster considerations into HIV/tuberculosis service delivery offers a pathway to strengthen overall health system resilience.