This line chart displays one week of temperature data in degrees Celsius for San Francisco, sourced from Data Canvas - Sense Your City. Despite its title, the visualization actually renders as a donut chart, using `d3.pie()` and `d3.arc()` to create proportional segments for each temperature category. The chart encodes values through color mapping with `d3.scaleOrdinal(d3.schemeCategory20b)` and includes an interactive legend that dynamically repositions labels based on their measured text width via `getBBox()`. The SVG output is styled with CSS classes for ticks, axes, and titles, though no actual line or axis elements appear in the code.