Dust storms are frequent in many arid and semi-arid regions of the world; they are a significant environmental hazard that impacts human health, agriculture, transportation, and ecosystems, and their frequency and intensity are being magnified by climate change and unsustainable land management practices. This study presents testing and validation of a Brightness Temperature Adjusted Dust Index (BADI), designed for enhanced detection and monitoring of dust storms, particularly under cloudy conditions. The proposed BADI integrates brightness temperatures from three Moderate Resolution Imaging Spectroradiometer (MODIS) thermal infrared bands: band 20 (3.66–3.84 µm), band 31 (10.78–11.28 µm), and band 32 (11.77–12.27 µm). The efficacy of the BADI was rigorously assessed through its application to several dust storm events over Iraq, including those occurring on April 9, 20, 2022, and March 03, 2022, all characterized by significant cloud cover. Validation involved a comparative analysis with real-time RGB dust storm imagery, derived from MODIS thermal bands (B29, B31, and B32), and corroborated with in-situ meteorological data from 13 stations across Iraq. Results consistently demonstrate that the BADI exhibits superior accuracy in delineating the spatial extent and density of dust storms, even when obscured by cloud cover. Furthermore, the BADI showed strong congruence with the real-time RGB dust storm images and perfect agreement with the ground-truth meteorological observations. These findings affirm the BADI as a highly effective tool for precise and timely monitoring of large-scale dust storm phenomena, representing a significant advancement in atmospheric remote sensing capabilities.