Table 2:

Correlations between daily air pollutant and weather variables for Wake County NC from March 1 2013 to February 28 2015

	CO	NO2	O3	PM25	SO2	Temperature	Relative humidity
CO	1	0.66	−0.10	0.45	0.40	−0.33	−0.10
NO2	0.66	1	−0.00	0.36	0.40	−0.44	−0.40
O3	−0.10	−0.00	1	0.22	−0.06	0.37	−0.42
PM25	0.44	0.36	0.22	1	0.18	−0.11	−0.11
SO2	0.40	0.40	−0.06	0.18	1	−0.53	−0.37
Temperature	−0.33	−0.44	0.37	−0.11	−0.53	1	0.27
Relative humidity	−0.10	−0.40	−0.42	−0.11	−0.37	0.27	1

CO: carbon monoxide

NO₂: nitrogen dioxide

O₃: ozone

PM_2.5: particulate matter under 2 μg/m³ in aerodynamic diameter

SO₂: sulfur dioxide