A multi-line chart displays one week of temperature data in Celsius for cities worldwide, sourced from Data Canvas – Sense Your City. Each line represents a city, colored via a categorical scale, with a legend and axes labeled for time and temperature. Built with D3 v5, the code uses `d3.csv`, `scaleTime`, `scaleLinear`, `scaleOrdinal`, `axisBottom`, `axisLeft`, `line` with `curveBasis`, and `nest` to group by city. The SVG rendering includes gridlines, a title, and smooth curved paths.