Please see the RG links below.

Article Effect of weather on COVID-19 spread in the US: A prediction...

Preprint Warmer weather and global trends in the coronavirus COVID-19

Good question. I think more data is needed to evaluate if and how weather is a factor in the spreading of COVID-19. On Africa it has confirmed cases in Egypt, Algeria, and Nigeria as of March 3, 2020... more countries may be confirmed in the future.

I just read one paper on this regard. This paper was submitted on 2nd March and was accepted on 3rd. They dont have even one word of weather.

On the origin and continuing evolution of SARS-CoV-2

Xiaolu Tang, Changcheng Wu, Xiang Li, Yuhe Song, Xinmin Yao, Xinkai Wu, Yuange Duan, Hong Zhang, Yirong Wang, Zhaohui Qian ... Show more

Author Notes

National Science Review, nwaa036, https://doi.org/10.1093/nsr/nwaa036

Published: 03 March 2020

In regard to the climate situation and its effect on the spread of the virus, it is known that the COVID-19 virus started its activity at the beginning of the cold season and in regions where the temperature is low. Autumn and Winter are the favored seasons for the spread of viruses in general. Often, the incidence rate decreases as we approach summer. However, the case may be different from the COVID-19 virus, because of its genetic composition. The COVID-19 virus can survive in the open air (on surfaces) for several hours and has not yet proven its ability to withstand high temperatures or not, especially if it is protected with fluids such as saliva and mucus. It is interesting to note that the winter will not be completely absent from the earth, because it will start on the other side of the earth, for example in Australia. I think the challenge is the ability of the world as a human society to cooperate in containing the virus transparently, knowing that the prevalence rate around the world is increasing every day.

One factor that may contribute to a lower virus activity in summer is the seasonal increase of vitamin D (due to more sun exposure). Summer season and higher vitamin D were found in several studies to be associated with a lower incidence of viral infections. Read for example Article Epidemic influenza and Vitamin D

COVID 19 can be transmitted in all areas regardless of climate. Evidence suggest that weather condition may influence the transmission of SARS-CoV-2. The cold and dry condition may increase the spread. Reports suggest on the reduction of the disease with the onset of spring and summer and increase in winter. But as summer has approached in northern hemisphere countries it is still on rise. So, I think, we will have to wait till next winter to see its further effect.

Please have a look at the following link:

Preprint Effects of temperature and humidity on the spread of COVID-1...

Please see the RG links below.

Article Effect of weather on COVID-19 spread in the US: A prediction...

Preprint Warmer weather and global trends in the coronavirus COVID-19

Take a look at the following link also.

https://www.cebm.net/covid-19/do-weather-conditions-influence-the-transmission-of-the-coronavirus-sars-cov-2/