This example displays multi-city temperature time-series data as colored line charts. It fetches CSV data from a remote Gist and parses it with `d3.csvParse`, then renders an SVG graph using `d3.scaleTime`, `d3.scaleLinear`, `d3.axisBottom`, and `d3.axisLeft`. The `d3.line` generator draws each city’s temperature over datetime, with random HSL stroke colors assigned per city. Data is loaded asynchronously via `fetch`, and the visualization updates automatically once the dataset arrives.