| Term: | Design thawing index |
| Definition: | The cumulative number of degree-days above 0˚C, calculated by taking the average of the seasonal thawing indices for the three warmest summers in the most recent 30 years of record |
| Term: | Design thawing index |
| Definition: | The cumulative number of degree-days above 0 degrees Celsius, calculated by taking the average of the seasonal thawing indices for the three warmest summers in the most recent 30 years of record. |