Standardised Precipitation Index (SPI)

https://w3id.org/hacid/data/cs/climdex/indices/SPI <https://w3id.org/hacid/onto/data/Variable>

A drought measure specified as a precipitation deficit xsd:string
xsd:string Standardised Precipitation Index (SPI) 
xsd:string SPI 
xsd:string Measure of “drought” using the Standardised Precipitation Index on time scales of 3, 6 and 12 months. See [McKee et al. (1993)](#appendixa_refs) and the [WMO SPI User guide (World Meteorological Organization, 2012)](#appendixa_refs) for details.
Calculated using the [SPEI R package](https://cran.r-project.org/web/packages/SPEI/index.html). 

data from the linked data cloud