Spatiotemporal changes in Hourly Wet Bulb Globe temperature in Peninsular Malaysia

Global warming causes a temperature rise and alteration of other meteorological variables that directly or indirectly affect human comfort. The wet bulb globe (WBGT) incorporates the effects multiple to provide reliable measure thermal stress. Despite large significance WBGT on public health, studies related characterization trends assessment are limited in tropical humid region like Peninsular Malaysia due unavailability all required for such analysis. This study employed reanalysis data ERA5 assess characteristics changes hourly, daily, monthly, seasonal annual outdoor over peninsular period 1959–2021 using Liljegren method. values were classified into five categories stress levels defined by United States Department Army (USDA). mean daily PM varies from 21.5 °C central south elevated 30.5 western coastal region. It always reaches heat-related illness risk level (31.20 °C) afternoon during monsoon extreme conditions inter-monsoonal periods. trend analysis revealed an increase time scales. higher maximum was estimated regions, nearly 0.10 0.25 °C/decade. nighttime 0.24 °C/decade, while daytime 0.11 caused gradual expansion areas experiencing exceeding high-risk 5 h (11 AM 3 PM). information maps generated this can be used mitigation planning PM, where extremes have grown rapidly recent years.