| Correlation Coefficient Climatic indices | Anomaly in surface air temperature over Western Europe in the duration time of heat waves over western Europe | |||
| Case (1) | Case (2) | Case (3) | Case (4) | |
| NAO | −0.85053* | 0.250064 | 0.369849 | 0.786557* |
| SOI | −0.44131 | 0.110302 | 0.266473 | 0.452762 |
| EL?NINO 3.4 | −0.54957** | 0.286092 | 0.549594** | −0.973401* |