Different indices describe current drought or wetness at selected sites of MeteoSwiss' observation network. Indices are derived from primary meteorological measurements, and precipitation is the most important input. Some of the indices also consider evapotranspiration, which is depending on temperature, humidity, radiation and wind speed.

Indicator

Standardized Precipitation Index (SPI), 12 months

Standardized Precipitation Evapotranspiration Index (SPEI), 12 months

Water balance, 12 months

Soil moisture,

Soil water deficit,

Vegetation water deficit,

Agricultural Reference Index for Drought (ARID)