Vertical observations of volatile organic compounds: A one-year continuous dataset along a mountain-to-summit gradient (550–2,119 m a.s.l.) in the Fanjingshan National Nature Reserve, Southwest China

This dataset contains one‑year continuous observations of volatile organic compounds (VOCs) along a mountain‑to‑summit elevation gradient (550 m, 1,300 m, and 2,119 m a.s.l.) in the Fanjingshan National Nature Reserve, Southwest China, from March 2024 to February 2025. A total of 57 VOC species (C₂–C₁₂) were measured online by gas chromatography with flame ionization detection (GC‑FID) at hourly resolution. Co‑located measurements of O₃, NOₓ, CO, and meteorological parameters (temperature, humidity, wind speed/direction, pressure) are also included. The data have been rigorously validated (detection limits ≤0.1 ppb for 90 % of species, accuracy and precision within ±10 %). Three CSV files (one per elevation) and a detailed README.txt are provided. The dataset is released under a CC BY 4.0 license. It can serve as a benchmark for chemical transport models (e.g., GEOS‑Chem, CMAQ), satellite HCHO column validation (e.g., TROPOMI), and process studies of vertical exchange in mountainous atmospheres.