Spatiotemporal Heat Index Assessment in the Monterrey Metropolitan Area during Heat Wave occurrence

Abstract. The rise in global temperatures has become a concern as every year reaches new record high temperatures and heat wave occurrences are more common. Alongside with this, worldwide population has also increased, resulting in highly urbanized areas where mitigation and adaptation to extreme heat has only just started to be considered in order to improve citizens’ quality of life and health. The Monterrey Metropolitan Area is characterized by semi-arid climate conditions which pose significant environmental challenges related to environmental resilience and recently, extreme heat conditions. In this research, the heat wave occurrences of 2023 and 2024 in Monterrey were evaluated using the Heat Index (HI) metric, information from the Air Quality and Climate Monitoring Network of Nuevo León and satellite temperature imagery from the Mexican National Meteorological Service in order to determine the most vulnerable areas and the health threats that high temperatures may cause. The resulting HI calculated using the ArcGIS Pro Heat Index function alongside the Inverse Distance Weighted spatial interpolation method indicate that Heat Index values depend on relative humidity percentages beside temperature, as higher humidity levels are linked to an increase in HI. The Monterrey Metropolitan Area can experience HI of more than 30°C, making the risk of heat stress most likely to occur. It is recommended to the population to be extremely cautious if exposed to the heat for long periods and to avoid outdoor activities if possible if the Heat Index exceeds the 41°C.