This visualization displays the monthly minimum and maximum temperatures for each year from 1997 to 2017, using a grid of colored rectangles where opacity encodes the coldest recorded temperature. The data is sourced from the temperature_daily_1.csv file, and the visualization is rendered as SVG using D3 v5. The code employs d3.scaleBand for the axes, d3.scaleLinear for color opacity mapping, and d3.axisTop/axisLeft to generate the chart structure. A legend with a linearGradient is also included.