This scatter plot visualizes temperature readings over time in San Francisco, with time on the x-axis and temperature on the y-axis. The code uses D3 v5 functions including `scaleTime`, `scaleLinear`, `axisBottom`, `axisLeft`, and `extent` to construct the chart, rendering purple semi-transparent circles as SVG elements. Data is loaded from a CSV file via `d3.csv` and converted to Date and numeric types. Grid lines are drawn via tick sizing, and axis labels are added as SVG text elements.