  The infectious coronavirus disease 2019 (COVID-19) has become a serious
global pandemic. Different studies have shown that increasing temperature can
play a crucial role in the spread of the virus. Most of these studies were
limited to winter or moderate temperature levels and were conducted using
conventional models. However, traditional models are too simplistic to
investigate complex, non-linear relationships and suffer from some
restrictions. Therefore, we employed copula models to examine the impact of
high temperatures on virus transmission. The findings from the copula models
showed that there was a weak to moderate effect of temperature on the number of
infections and the effect almost vanished under a lockdown policy. Therefore,
this study provides new insight into the relationship between COVID-19 and
temperature, both with and without social isolation practices. Such results can
lead to improvements in our understanding of this new virus. In particular, the
results derived from the copula models examined here, unlike existing
traditional models, provide evidence that there is no substantial influence of
high temperatures on the active COVID-19 outbreak situation. In addition, the
results indicate that the transmission of COVID-19 is strongly influenced by
social isolation practices. To the best of the author knowledge, this is the
first copula model investigation applied to the COVID-19 pandemic.
