Multi-Series Line Chart
This visualization displays the daily average temperature for New York, San Francisco, and Austin over a year, with three colored lines allowing direct comparison of seasonal patterns. The chart uses D3 v3 APIs, including `d3.tsv` for data loading, `d3.time.format` for date parsing, `d3.time.scale` for the x-axis, `d3.scale.linear` for the y-axis, and `d3.scale.category10` for color encoding. It renders with SVG, using `d3.svg.axis`, `d3.svg.line`, and `d3.keys` to structure city series from the TSV data.