The Standardized Precipitation Index (SPI) was generated for certain Environment Canada long-term climate stations in Ontario. The SPI quantifies the precipitation deficit and surplus for multiple time scales , including: * one month * three months * six months * nine months * 12 months * 24 months You can use the SPI to study the impact of dry and wet weather conditions to create comprehensive water management approaches. The SPI data package is distributed as a Microsoft Access Geodatabase. __This is a legacy dataset that we no longer maintain or support.__ The documents referenced in this record may contain URLs (links) that were valid when published, but now link to sites or pages that no longer exist.