A multi-line chart displays daily temperature readings for New York, San Francisco, and Austin from October 2011 through April 2012, with each city represented by a colored line. Built with D3 v7, the visualization supports interactive filtering: hovering over a city name highlights its line while dimming others, and clicking toggles a line's visibility. Users can also brush or zoom along the time axis. The SVG-based rendering uses d3.line with curveBasis, d3.scaleTime, d3.scaleLinear, and d3.zoom, with data loaded from a TSV file.