This example displays the average yearly temperature in Dallas from 2015 to 2023, drawing a single smooth line that reveals the overall warming trend across nine years. The visualization is built with D3 v7, using `d3.csv` to load the monthly temperature data, `d3.rollup` to group records by year and calculate the mean, and `d3.line` with `curveMonotoneX` to render the SVG path. Gridlines are generated with `d3.axisBottom` and `d3.axisLeft`, and the chart is presented on a 900×500 SVG canvas with labeled axes and a bold title.