A line chart displays a week of temperature readings (in Celsius) for multiple cities, sourced from Data Canvas – Sense Your City. Each city has its own colored path, rendered as smooth curves using `d3.line` with `curveBasis`, and a legend built via a custom `colorLegend` function. Axes use `axisBottom` and `axisLeft` with grid lines, while data is nested by city using `d3.nest` and sorted by final temperature. The visualization is implemented with D3 v5 and SVG, featuring a title and axis labels.