This visualization shows the average yearly temperature in Dallas from 2015 to 2023, using a smooth area chart to highlight the overall trend. Monthly temperature readings from the CSV file are aggregated into yearly averages, and the area fill is drawn beneath a monotone curve. The code uses D3 v7 with `d3.area()`, `d3.rollup()`, `d3.mean()`, and `d3.scaleLinear()` to compute and render the data, with grid lines from `d3.axisBottom()` and `d3.axisLeft()` for readability.