Heatwaves pose a significant threat, causing not only direct heat-related health issues but also triggering cascading failures such as prolonged blackouts due to heightened electricity demand for air conditioning, and diminished crop productivity, straining the food-water-energy nexus. Using ground-based wet-bulb temperatures from 1971 to 2023, this study examines trends in humid (moist) heatwaves in South Asia (SAS) and the Middle East and North Africa (MENA) regions. It defines humid heatwaves as instances where daily maximum wet-bulb temperatures exceed predefined thresholds (for moderate: 85th and extreme: 90th percentiles) over a 31 day rolling window, referencing to a 30 year (1981–2010) climatology. The study compares block maxima versus threshold-based indices along with durations of events to detect moderate to severe humid heatwave conditions over the SAS and MENA regions. We assessed the decadal trends in humid heatwaves using Sen’s slope method, while the significance of detected trends was determined via bootstrap procedures. We show an increasing trends in humid heat stress across 26–34% of locations, contrasted by decreasing trends in 13–15% of sites. Understanding space–time trends in heatwaves is crucial for implementing effective mitigation and adaptation planning for the present-day as well as for developing climate-resilient adaptation practices for future scenarios.