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.