Two SVG charts display monthly weather data for multiple U.S. cities from `city_temps.csv`. The multi-series line chart draws separate lines for temperature, rainfall, and humidity per city using `d3.line`, `d3.scaleLinear`, and `d3.scaleOrdinal`. A combined chart juxtaposes Dallas rainfall as bars with a temperature line on the same axes, using `d3.scaleBand` and `d3.axisBottom`. Both charts use SVG rendering with D3 v7 selection and data-binding APIs.