<p>Understanding aerosols' behaviour over semi-arid urban regions is critical for assessing air quality and its climatic implications. This study investigates the spatiotemporal alteration of Aerosol Optical Depth (AOD) over Jaipur, India, using Moderate Resolution Imaging Spectroradiometer (MODIS) satellite data at 0.47&#xa0;µm and 0.55&#xa0;µm wavelengths, and 0.50&#xa0;µm from the ground-based AErosol RObotic NETwork (AERONET) site for 2018 to 2024. The objective is to analyse seasonal patterns, detect long-term trends, and assess the relationships between various wavelengths of AOD and Particulate Matter (PM₁₀ &amp; PM_2.5) collected from ground-based stations. Monthly AOD showed consistent seasonal peaks during the pre-monsoon months, with maximum values in May 2023 and the lowest concentrations during the monsoon due to effective wet deposition. Linear regression analysis across AOD wavelengths showed weak declining trends, with statistical significance observed only at 0.50&#xa0;µm (slope ≈ − 0.002 per month, <i>p</i> &lt; 0.05) and <i>R</i>² values below 0.06, confirming a poor linear fit and highlighting episodic variability. Pearson correlation analysis revealed a high degree of association between AOD values at 0.47&#xa0;μm and 0.55&#xa0;μm wavelengths, indicating consistency in aerosol spectral behaviour across these channels. Robust anomaly analysis (|<i>Z</i>|≥ 2.5) identifies recurrent extreme aerosol loading events, particularly during pre-monsoon, winter, and post-monsoon periods, underscoring the role of short-term processes in shaping AOD variability. These correspond to episodic aerosol events such as regional dust transport, biomass burning, or festival-related emissions. These findings emphasise the importance of high-frequency monitoring and event-based analysis to support urban air quality regulation and climate resilience planning in regions like Jaipur.</p>