Heat waves and their impacts on the intensity of the intra-urban heat island in São Caetano do Sul, São Paulo.

Abstract

Heat waves (HW) are extreme atmospheric phenomena that significantly impact various sectors of society. This study aims to assess HW in the municipality of São Caetano do Sul, São Paulo, and its effects on intra-urban heat islands (HI). Over 25 years (1999-2023), 131 HW events were recorded in the municipality, with these events occurring more frequently during the summer and spring seasons. The maximum temperature threshold identified was 34°C. The findings revealed that during HW events, the maximum intensity of intra-urban heat increases by up to 3°C above the average value of 5.7°C. Additionally, the duration of high temperatures extends from 5 PM to 11 PM, which adversely affects the thermal comfort of the population. Notably, HW events were found to be more extreme in spring (September and October), leading to an even greater intensity of intra-urban heat.