This line chart displays the monthly average wind speeds for various cities in 2016, with each city represented by a distinct colored line and a circle marker at each data point. The visualization uses D3.js (v6) to load CSV data, group it by city with `d3.group`, and render lines with `d3.line` and scales from `d3.scaleLinear`. A color legend is created using the `d3-legend` library, and the SVG output includes axis labels for months and wind speed.