A Machine Learning Approach to Predict Air Quality in California

Table 1

Summary of measurement sites and observed variables.

Measurement sites	Type	Variables
California	Meteorological conditions	Outdoor temperature
		Relative humidity
		Wind speed
	Criteria gases	Carbon monoxide
		Ozone
		Sulfur dioxide
		Nitrogen dioxide (NO2)
	Particulates	PM2.5

The pollutant data are expressed in units of mass concentrations, i.e., mg/m³ (ppm), except for NO₂, which is measured in ppb.