| Annual average mass concentration of anion with- | Annual average temperature | Annual rainfall days | Annual precipitation | Annual lightning days | Annual hours of sunshine | Annual average relative humidity |
| R | −0.861 | 0.576 | 0.730 | 0.672 | −0.803 | 0.246 |
| Significance test | No correlation | No correlation | 0.031 | No correlation | 0.058 | 0.049 |