20250318 16431800 1.0 TRUE The Standardized precipitation index (SPI) is a widely used index to characterize meteorological drought on a range of timescales. The SPI can be compared across regions with markedly different climates. It quantifies observed precipitation as a standardized departure from a selected probability distribution function that models the raw precipitation data. The raw precipitation data are typically fitted to a gamma or a Pearson Type III distribution, and then transformed to a normal distribution. The SPI values can be interpreted as the number of standard deviations by which the observed anomaly deviates from the long-term mean. The SPI can is computed for differing periods of 1 to 60 months. For more information, visit: https://open.canada.ca/data/en/dataset/4ae5b0d1-b811-4238-9aed-ce97363f51eb Standardized precipitation index (SPI). Agriculture and Agri-Food Canada © Government of Canada (2025). Data are subject to the Government of Canada Open Data Licence Agreement: https://open.canada.ca/en/open-government-licence-canada. The terms of this Agreement govern your use and reproduction of the data instead of the copyright reproduction statements found in Important Notices on the Agriculture and Agri-Food Canada website. Climate Weather Precipitation SPI Standardized precipitation index