This multi-line chart displays temperature measurements over time for multiple cities, with each city represented by a distinct colored line. The visualization uses d3.csv to load the dataset and d3.nest to group data by city, then renders smooth curves with d3.line and curveBasis. Axes are created using d3.axisLeft and d3.axisBottom, with scales from d3.scaleTime and d3.scaleLinear, while colors are assigned via d3.scaleOrdinal with schemeCategory10. SVG rendering with grid lines and axis labels completes the chart.