Climatological normal
Climatological normal is a 30-year average of a weather variable. Climatological normals are used as an average or baseline to evaluate climate events and provide context for year-to-year variability. Normals can be calculated for a variety of weather variables including temperature and precipitation and rely on data from weather stations. Variability from the 30-year averages is typical and climate variability looks at the magnitude of extremes. The current normals period used, for example, is 1981-2010.
