1 text/xml image/tiff image/png image/png24 image/png32 image/bmp image/gif image/jpeg image/svg image/bil XML INIMAGE BLANK 0 The Standardized Precipitation Index (SPI) is widely regarded as one of the most accessible tools for quantifying and reporting meteorological drought. At shorter timescales, SPI values are highly correlated with soil moisture, while at extended timescales, they reflect variations in groundwater and reservoir storage. The SPI model derives probability distributions from historical precipitation records, which are then normalized using an incomplete gamma function across multiple timescales. SPI values indicate the number of standard deviations the observed anomaly departs from the long-term period of record, with positive values corresponding to wetter-than-average conditions. These values are intended to provide an overall assessment of agricultural growing conditions within a region for a specified time period. On the monthly scale, time periods calculated are 1, 2, 3, 6, 9, 12, 18, 24 months. On the weekly scale, each ISO week is numbered from 1 to 52 (sometimes 53) within a year. An ISO week starts on Monday and ends on Sunday. The time periods can be filtered using the tType field in the service where a suffix "m" denotes a monthly time scale and "w" denotes a weekly time scale. Historical record goes back to 1980. Indices values were calculated using the xclim python package. For more information, visit: https://open.canada.ca/data/en/dataset/cdc59a23-ca37-4645-b96d-4e7737404e54 CRS:84 EPSG:4326 EPSG:3857 -179.999996179.88082617.18590285.051129 standardized_precipitation_index:nasdi_standardized_precipitation_index 2015-01-11T12:00:00.0Z/2026-04-26T12:00:00.0Z/P1S standardized_precipitation_index:None 2015-01-11T12:00:00.0Z/2026-04-26T12:00:00.0Z/P1S 2015-01-11T12:00:00.0Z/2026-04-26T12:00:00.0Z/P1S