This area chart visualizes temperature data over time, loading a CSV dataset and displaying daily temperature points connected by a filled band. The example uses D3 v7 to render an SVG chart with animated tooltips that appear on mouseover, showing the city, date, and temperature in Celsius. The area is drawn using `d3.area` with a steelblue fill, while individual data points are marked with circles. The x-axis labels are rotated, and the chart includes a title. Tooltips are implemented with a styled overlay that fades in and out on user interaction.