This example shows a temperature-over-time chart for San Francisco, using a D3 CSV loader to fetch weekly data and rendering it as an SVG line graph with circular data points. React handles the component structure, while D3’s `scaleTime`, `scaleLinear`, `extent`, and `line` with `curveNatural` compute scales and draw the smooth path. The code also builds custom axes with `ticks()` and uses `timeFormat` for weekday labels on the x-axis. Native SVG `<title>` elements provide tooltips on hover.