Heatwave-induced thermoregulatory stress in Odisha's coastal and north-eastern districts: Examining the April 2024 event using advanced statistical and geospatial techniques

This work investigates the remarkable heatwave that struck Odisha in April 2024, with special emphasis on intensity and duration in the coastal and interior regions. It is of special concern if such patterns arise in coastal districts where comfortable weather is due to the proximity of the sea. There's been an uninterrupted recording of temperatures crossing 40°C for 16 consecutive days i.e., from the 15th to the 30th of April which includes some regions usually considered less vulnerable to extreme heat. The aim of this particular research is focused on synoptic features and focuses on drivers for the specific anomaly in northeastern and coastal districts. The study utilises the historical temperature dataset ranging from 1969 to 2024, applying the heat wave trends according to the IMD classification and 90th percentile threshold. The examination of synoptic features of atmospheric circulation along with vertical thermal structures is the main scope of this research. From data collection, it is observed that there is an exacerbating increase in the frequency and intensity of heat waves alongside UHI effects, and they are linked with transitions of El Niño–La Niña. Along with this, stepping over vegetation and the increase in impervious surfaces also led to delayed sea breeze onset and higher heat retention in coastal zones. With the quantitative analysis that was supplemented by the UHI phenomenon, it was revealed that Thom's discomfort index also displayed significant discomfort to the inhabitants of the area during the heatwave, with values exceeding 28 in most locations, indicating severe discomfort levels. Unlike prior research in Odisha that primarily focused on long-term trends or socio-economic vulnerability, this study uniquely applies high-resolution WRF simulation, satellite reanalysis, and thermoregulatory indices to capture the April 2024 heatwave’s spatial variability, urban–coastal thermal interactions, and atmospheric drivers in an integrated and operationally relevant framework. These findings underscore the urgency of developing adaptive strategies such as urban planning reforms (e.g., greening and zoning), early warning systems tailored to heat thresholds, and region-specific public health interventions to protect vulnerable populations in Odisha and similar coastal environments.