Table 2 Spearman correlations between the numbers of DNCCs of COVID-19 and meteorological factors

− 0.63*

− 0.57*

− 0.28*

− 0.26*

− 0.23*

0.17*

− 0.45*

− 0.52*

0.3*

0.04

− 0.21*

− 0.11*

− 0.01

− 0.05

− 0.21*

− 0.25*

0.58*

− 0.05

− 0.21*

0.15*

0.29*

0.13*

− 0.24*

− 0.39*

− 0.77*

− 0.41*

− 0.12*

− 0.19*

− 0.01

0.07

− 0.18*

− 0.38*

− 0.43*

− 0.18*

0.02

0.02

− 0.49*

− 0.09

0.35*

0.31*

0.36*

0.19*

0.13*

0.02

− 0.24*

− 0.26*

0.23*

0.33*