This bar chart visualizes the average annual temperature across several U.S. cities, derived from monthly city_temperature.csv data. Each bar represents one city, with heights mapped to the mean of its recorded monthly temperatures. Built with D3 v7, the SVG chart uses d3.rollup and d3.mean to aggregate monthly values per city, d3.scaleBand and d3.scaleLinear for positioning, and includes interactive hover tooltips that display the exact average temperature while highlighting the bar. Axis labels and rotated city names aid readability.