This multi-line chart displays a week of global temperature readings across multiple cities, using color-coded lines to distinguish each location. The visualization is built with React and D3 v5, rendering SVG paths with smooth curves via `d3.line` and `curveBasis`. The data, loaded from a CSV file, is processed with `d3.nest`, while axes and scales are created using `d3.axisLeft`, `d3.axisBottom`, `scaleTime`, and `scaleLinear`. A custom color legend, driven by `scaleOrdinal` and `schemeCategory10`, animates with `transition().duration(1000)`.