Table 1. The list of nine climatic variables used with Multivariate Geographic Clustering (MGC) for initial development of the NEON Domain map is shown in the table below.
| Map Layer or Variable Name |
| Number of days above 90°F during the local growing season |
| Number of days below 32°F during the local non-growing season |
| Precipitation sum during the local growing season |
| Precipitation sum during the local non-growing season |
| Number of days with measurable precipitation during the local growing season |
| Number of days with measurable precipitation during the local non-growing season |
| Soil plant-available water holding capacity to 1.5 m |
| Total solar insolation during the local growing season, including clouds, aerosols, slope and aspect physiography |
| Total solar insolation during the local non-growing season, including clouds, aerosols, slope and aspect physiography |