| Index type | Index | Specific definition |
| Extreme high temperature index | Number of summer days (SU, d) | All days of the year where the maximum daily temperature is >25˚C |
| Extreme maximum temperature (TXx, ˚C) | The maximum daily maximum temperature during the year | |
| Extreme low temperature index | Number of frost days (FD, d) | All days of the year where the lowest daily temperature is less than 0˚C |
| Extreme minimum temperature (TNn, ˚C) | The minimum daily minimum temperature during the year |