The spreading of the PRRS virus has recently been assumed to travel further in cold weather conditions. This was proven in past experiments and has since been considered the meteorological factor involved in PRRS spreading. Although it is true that cold weather is a factor in the survival of the virus it may  not be the only factor. The tests done to uncover weather factors involved a swine operation which was PRRS positive and 3 outlying facilities located 120 meters away in the direction of the prevailing winds. Two conclusions drawn from the research was that the virus was aerosol transported in all months except August and July and parameters other than temperature were a factor. It was noticed that air spreading viruses occurred not only in the winter but in the spring and summer months of April, May, and June. Also, meteorological parameters such as wind direction, relative humidity, barometric pressure and ultraviolet light index were found to be significant predictors of the PRRS virus in air. Although more work is required to legitimize some of these findings, producers can take away that prevailing winds should be a factor when deciding where to build new facilities.