Colorado Climate Center
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Colorado Drought Status Briefing

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Standardized Precipitation Maps


The Standardized Precipitation Index (SPI) was developed for the purpose of defining and monitoring drought. Among others, the Colorado Climate Center, the Western Regional Climate Center, and the National Drought Mitigation Center use the SPI to monitor current states of drought in the United States.

For more information on the methodology behind SPI, click on either a PostScript version or an Adobe PDF version of Chapter 3 of Dan Edwards' Masters Thesis. This document details the mathematics used in SPI calculation.

For source code for a simple SPI program, click here for Unix tar format or zip format.

SPI Archive
2013 2012 2011 2010 2009 2008 2007 2006 2005 2004

Latest Conditions

Projected Conditions at 0.2 Probability Level

Projected Conditions at 0.5 Probability Level

Projected Conditions at 0.8 Probability Level


Data Access Links > Current Weather: ColoradoUSAWorld  | Water Year Data: Colorado  |   Long Term Climate: ColoradoUSAWorld  

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Fort Collins, CO 80523-1371

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