Meteorological Drought Duration

https://w3id.org/hacid/data/cs/Climate-ADAPT/indices/MeteorologicalDroughtDuration <https://w3id.org/hacid/onto/data/Variable>

xsd:string Meteorological Drought Duration 
xsd:string The count of months in a year with anomalously low precipitation conditions based on the 3-month Standardised Precipitation Index (SPI-3) relative to a reference period, here 1981-2010 (month). A drought event starts when SPI-3 values fall below -1 for at least two consecutive months and ends when the index returns positive. 

data from the linked data cloud