From the probabilistic Weiss equation, various relations involving the distance, wind velocity and number of people both healthy and infected, the critic distances that might be critic to transmit any virus strain, are calculated. The present approach considers as main criterion that the outdoor infection is a random event that depends of a plethora of variables and free parameters. We project the present theoretical proposal to the current Corona Virus Disease 2019 pandemic by which is established that people must keep a social distance ranging between 1.5m and 2.0m in order to avoid contact with aerosol. In this paper stochastic and deterministic equations are proposed as well as hybrid relationships that would explain facts in the action of outdoor infection. In this manner virus can be transmited in a radius of 2m for a wind velocity of 10m/s.