This heatmap visualizes impact magnitudes across locations and months from January to September 2016, using color intensity to convey variation. The D3.js v7 code loads CSV data via `d3.csv`, maps locations and months to x- and y-axes using `d3.scaleBand`, and fills rectangles with the sequential `d3.interpolateViridis` color scale. The SVG rendering includes axis labels, a chart title, and a grey background, with the heatmap cells styled with rounded corners and white strokes.