A line chart displays hourly temperature readings in San Francisco over a week in March 2015, with time on the x-axis and temperature on the y-axis. The graph uses a smooth curve to connect data points, showing a daily pattern of cooler nights and warmer afternoons. Built with D3 v5, the visualization loads data from a CSV file and renders an SVG using `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and the `line` generator with `curveBasis`.