Reproduction of Indian High Temperature Patterns: A CMIP6 Model Evaluation

Abstract

High temperature (HT) over India has garnered increasing attention in recent years due to their substantial impact on human health and well-being. Given their growing significance, extensive efforts have been made to understand the driving mechanisms behind these events, as well as their projected changes under future climate scenarios using global climate models (GCMs). However, confidence in such projections depends critically on how well GCMs can replicate historical climate behaviour. In this study, we evaluate the performance of models participating in Phase 6 of the Coupled Model Intercomparison Project (CMIP6) in capturing the spatio-temporal characteristics of HT over India. Observational data reveal two distinct patterns: (i) an increasing trend in HT over southwestern India (SWI), and (ii) a pronounced east–west asymmetry over northern India, characterised by more frequent HT in the northwest and a decline in the east. The SWI HT pattern is closely linked to the El Niño–Southern Oscillation, which is reasonably well represented by the CMIP6 models. In contrast, the models fail to reproduce the observed asymmetry in northern India, likely due to their inadequate simulation of the large-scale atmospheric response to the Atlantic Niño. These findings underscore the importance of rigorous model evaluation before relying on CMIP6 projections to inform HT-related adaptation and policy strategies in a highly vulnerable region like India.