This line chart displays one week of temperature data for cities worldwide, sourced from the Data Canvas - Sense Your City initiative. The visualization plots time on the horizontal axis and temperature in degrees Celsius on the vertical axis, with each city represented by a distinct colored line. Built with D3 version 5, the code uses `scaleTime`, `scaleLinear`, and `scaleOrdinal` for scales, along with `axisBottom` and `axisLeft` for axes. A `nest` operation groups data by city, and a custom `colorLegend` function renders the categorical color key. Multiple lines are drawn using `line()` with a basis curve, rendered as SVG paths.