Droughts are complex phenomena with a multitude of definitions mainly dependent on their timing/duration and associated impacts. In general, they refer to prolonged periods of time with abnormally below average moisture conditions, during which limitations in water availability result in negative impacts for various components of natural systems and economic sectors. CMIP6 multi-model drought projections on seasonal to annual time scales are available for Canada over the twenty-first century for three emission scenarios: SSPs 1-2.6, 2-4.5 and 5-8.5.
Variables include the Standardized Precipitation Evapotranspiration Index (SPEI), Standardized Runoff Index (SRI), and Standardized Soil Moisture Index (SSI), representing meteorological, hydrological, and agricultural droughts, respectively. Intermediate datasets are also available, including potential evapotranspiration (PET), water balance (monthly precipitation minus PET), climate moisture index (CMI; annual precipitation minus PET), actual surface soil moisture, and actual surface runoff.