Long-term monthly records of lake dynamics are critical for understanding hydrological and climatic change on the TP. However, existing products are constrained by factors such as cloud cover, snow and ice contamination, terrain shadow, observational gaps, and scale-related bias. Here we present a new monthly dataset of lakes larger than 1 km² across the TP for 2001–2025 at 30 m spatial resolution. The dataset was generated using TSRFD framework integrating MODIS, Landsat and terrain variables, with refinement steps to improve mapping accuracy and boundary consistency. Technical validation against three reference datasets showed strong spatial agreement (IoU = 0.80–0.92) and very high consistency in lake area estimates (R² > 0.99). Uncertainty analysis indicated that most lake-months were classified as having low to moderate uncertainty. From 2001 to 2025, lakes on the TP expanded in both number increasing by 20.6 % and total area expanding by 22.9 %, despite interannual variability. Small lakes contributed to the increase in lake number, while larger lakes were responsible for most to area expansion. Both metrics showed clear seasonal peaks in late summer. This dataset provides a valuable long-term resource for investigating lake dynamics, hydrological variability, and climate-lake interactions in high-altitude regions.