cedar.metrics.cdd¶

Cooling Degree Days (CDD) helper.

Computes per-hour degree exceedance above a base temperature. This is a simple utility: given ambient temperatures, it returns the positive difference from the base (°K) and zero otherwise. Daily/monthly aggregation is left to callers (xarray resampling, summing, etc.).

Example

>>> cdd = CoolingDegreeDays(base_temperature_K=18.0 + 273.15)
>>> cdd.exceedance([290.0, 293.0, 296.0])  # mix of below/above base
array([0.  , 1.85, 4.85])
>>> cdd.exceedance([270.0, 273.0])         # below base → zeros
array([0., 0.])

Classes

CoolingDegreeDays([base_temperature_K])

Compute hourly CDD exceedance against a base temperature.