Table 1: Results of comparisons of mean weather variables between PRRSV-positive and PRRSV-negative days [14].
| Variable | Air samples | p-Value | |
| PRRSV (-) | PRRSV (+) | ||
| Barometric pressure (hectoPascals) | 981 | 982 | 0.83 |
| Temperature (°C) | 3.2 | 7.1 | 0.4 |
| Relative humidity (%) | 88 | 89 | 0.83 |
| Wind velocity (m/s) | 1.2 | 2.9 | 0.001 |
| Wind gusts (m/s) | 2.1 | 4.6 | 0.004 |
| Sunlight intensity (Watts/m2) | 19.0 | 7.2 | 0.06 |
| Sunlight intensity (measure of photons in the visible light spectrum (400-700 nm) μmol/m2/s) | 51.0 | 21.0 | 0.09 |
| Precipitation (mm) | 2.4 × 10-3 | 7.5 × 10-3 | 0.55 |