A line chart displays weekly temperature variations in San Francisco, with time on the x-axis and temperature on the y-axis. The visualization uses D3.js v5 to load CSV data, create scales with `d3.scaleTime` and `d3.scaleLinear`, and render an SVG path via `d3.line`. Axes are generated with `d3.axisBottom` and `d3.axisLeft`, and the data is fetched using `d3.csv`. The chart includes labeled axes and a title, with temperature values plotted against timestamps.