This visualization shows the average monthly temperature trend as a smooth line chart, with blue strokes highlighting temperature changes over time. The code loads weather data from a CSV file via the GitHub Gist URL, parses date and temperature fields, and aggregates daily readings into monthly averages using d3.rollups. The line is rendered with d3.line and d3.curveMonotoneX, with time and linear scales for axes. The chart includes labeled x- and y-axes, using d3.axisBottom and d3.axisLeft, and is built with D3 v7 within an SVG viewBox.