Heating Degree Day Normals
When we refer to current conditions being “warmer than normal” (or colder, or wetter, or drier, or…), we compare current conditions to averages over a 30 year climatological reference period, i.e. the statistical normal. The most recent reference period is 1991-2020. As the reference periods change, so does the statistical normal and the anomalies or “departures from normal” that we calculate based on the normal.
Select the tab of the desired climatological reference period, then select a station and time frame. The current reference period is 1991-2020.