This chart displays a week of temperature readings from multiple cities, with each city drawn as a colored line over time. The data is loaded from a CSV, parsed, and rendered as smoothed SVG paths using d3.line with curveBasis. Axes are generated with d3.axisBottom and d3.axisLeft, and a color legend is built using d3.scaleOrdinal with schemeCategory10. React manages the app shell, while d3.nest groups records by city for sorting.