This area chart displays average temperatures recorded over time, with a smoothed curve and filled region emphasizing temperature trends across years. The visualization uses D3 v5 (loaded via CDN) and renders to SVG. The code builds linear and time scales, draws axes with gridlines, and applies a curve-basis generator to both a line and an area path. Data comes from a CSV file parsed with d3.csv, with dates converted using d3.timeParse.