The aim of this study is to investigate the impact of climate conditions, altitude and population density on daily COVID-19 infections across the following six cities : Casablanca, New York, Madrid, Lombardy-Milan, Paris, Wuhan between the 1st February and 25th April 2020.The results show that for an average wind speed greater than 25 km/h ,the number of daily COVID-19 infections is slightly decreased with a rate of 10 %, while the temperature, humidity altitude factors didn’t show any clear impact on its evolution, furthermore, the population density strongly affects the progression of COVID-19 infections with an approximate rate of 90%. Finally, we have proposed a mathematical model to estimate the evolution of COVID-19 infections over time by taking into consideration simultaneously the wind speed and the population density effects.