This dataset contains sea surface temperature (SST) reconstructions derived from alkenone biomarkers measured in sediment core SO130_289KL (23°07.34′N, 66°29.84′E; 571 m water depth) collected from the northeastern Arabian Sea off the coast of Pakistan. The data focus on the Greenland Interstadial 1 (GI-1) interval (~14.7–12.9 ka), where finely laminated sediments allow high-resolution analysis. Measurements were performed using mass spectrometry imaging (MSI) on cryosectioned sediment slices with a spatial resolution of 200 µm. The dataset captures rapid SST variability associated with monsoon dynamics, including an abrupt warming of ~2°C during the transition from Heinrich Stadial 1 to GI-1. This dataset was generated to reconstruct high-frequency SST variability and assess the influence of South Asian monsoon systems on upper ocean conditions. Depth is presented as centimeters below seafloor (cmbsf) and age as before the year 2000 CE (b2k).