<b>BreatheAccra PM2.5 and ERA5 meteorology for Greater Accra, Ghana (April 2023 - February 2025): analysis dataset and reproducible code</b>

Quality-controlled daily PM2.5 from the BreatheAccra network of 62 corrected low-cost optical monitors across 19 municipal assemblies of the Greater Accra Metropolitan Area, Ghana, covering 1 April 2023 to 28 February 2025 (15,144 sensor-days), joined to co-located daily ERA5 and ERA5-Land meteorology. The deposit also contains the derived series, model outputs, publication-resolution figures and the complete Python pipeline that regenerates every number, table and figure in the associated paper. The pipeline depends only on NumPy, pandas and Matplotlib; the mixed-effects, penalized-spline and trend estimators are implemented from their defining equations.The dataset supports an analysis showing that the seasonal cycle of PM2.5 over Accra is bimodal, with a December-February harmattan maximum and a secondary July maximum coinciding with the shallowest and least insolated boundary layer of the year, and that the near-surface moisture predictors conventionally used in such analyses are severely collinear at this site.