<p>This paper analyzes the complex air quality changes observed after three years of the devastating Russian–Ukrainian war. Using remote sensing and near-surface observations for 2019–2024, we provide the first multi-temporal assessment of air pollutant changes, ranging from single events to interannual variability, against the background of the war’s cumulative regional effects. The analysis reveals contrasting short- and long-term impacts. Short-term episodes in urban areas linked to missile and drone attacks increased near-surface pollutant concentrations by 100–400%, with extreme cases exceeding 1000%, while average three-year changes reflected redistribution and shift of emission sources. These shifts produced heterogeneous outcomes: total suspended particles (TSP) mainly decreased in major cities but increased by 14% near the frontline; SO₂ rose in regions reliant on dirtier fuels; NO₂ generally declined by 10–30% with greater variability; and CO mostly decreased except near specific industrial sources. Satellite data confirmed a war-related regional pollution decrease up to 30% for NO₂ in major cities and near the frontline, 10% CO drop because of destructions in Mariupol and SO₂ decrease over the Donetsk region. A decrease in CH₂O of up to 12% observed in the northern Ukraine probably related to changes in the prevailing meteorological conditions. These findings highlight the war’s dual role in suppressing regular emissions while amplifying localized pollution.</p>