Table 3.

Results of Pearson correlation test

Variables	New cases for the three cities
Pearson correlation coefficient	Wind_speed	Diff_Temp	PM10	NO2	O3
Riyadh	-0.04***	0.46**	0.68***	0.48**	0.46**
Jeddah	-0.02	0.42	0.54***	0.37*	0.35**
Makkah	-0.07***	0.38**	0.36**	0.31*	0.29*

*** stands for 1% level of significance. ** stands for 5% level of significance. * stands for 10% level of significance