Intensities of the 2023 and 2024 heatwaves in different local climate zones of the city of Puebla (Mexico)

Abstract

In 2023 and 2024, Mexico experienced intense heatwaves that affected large areas of the country. This article evaluates the differentiated responses of three events in 2023 and four in 2024 in five local climate zones (LCZ) in the city of Puebla (Mexico). Heatwaves were identified based on the criterion of five consecutive days in which daily temperatures exceeded the 90th percentile, applied to the maximum temperature (27.4 ºC) for diurnal waves and to the minimum temperatures (17.4 ºC) for nocturnal waves. When thermal thresholds were exceeded during both day and night over the same period, waves were classified as circadian. To achieve greater precision, the wave’s intensity was calculated in degree-days and degree-hours. Additionally, the Humidex index was applied to estimate the bioclimatic effects in degree-hours above the preferred Humidex value. The findings indicate that nocturnal waves in the city center are more intense, partly due to the urban heat island effect, and that LCZ with greater vegetation show increased wave intensity when atmospheric humidity is included in the analysis. Thermohygrometric data recorded every 15 min at five meteorological stations throughout 2023, and six months of 2024, were used. Given the limited number of studies in Mexico evaluating the spatially differentiated effects of heatwaves within urban areas, this study adopts a localized approach