| Number of variables | Variables names | ρ |
| 1 | CML attenuation | 0.94 |
| 2 | CML attenuation, Dew point | 0.97 |
| 3 | CML attenuation, Dew point, Wind speed | 0.95 |
| 4 | CML attenuation, Dew point, Wind speed, Atmospheric pressure | 0.95 |
| 5 | CML attenuation, Dew point, Wind speed, Atmospheric pressure, temperature | 0.95 |
| 6 | CML attenuation, Dew point, Wind speed, Atmospheric pressure, temperature, Wind direction | 0.95 |