Locate and download USDM data

This tutorial uses California drought data from the United States Drought Monitor (USDM), a service jointly produced by the National Drought Mitigation Center at the University of Nebraska-Lincoln, the United States Department of Agriculture, and the National Oceanic and Atmospheric Administration. The USDM monitors drought severity nationwide and publishes weekly drought severity metrics on a categorical scale of 0-4 from "Abnormally Dry" to "Exceptional Drought." This tutorial uses county-level drought severity data in California for 2018. See the What is the USDM? page on the USDM website for more details about the drought severity scale and the types of data available.

Download the Drought Monitor dataset

Follow these steps to download the appropriate data from the website. Alternatively, download the us_drought_monitor.csv.zip file directly.

1. Navigate to Data > Data Download > Comprehensive Statistics in the USDM website.
2. Input the following information:

   Field in Data Download page	Value	Notes
   Start Date	01/01/2018	You are going to map drought severity for the year 2018.
   End Date	12/31/2018
   Spatial Scale	County	The spatial scale you select determines the spatial granularity of the data, which needs to match the granularity of the geospatial lookup file you download in the next step.
   Statistics Category	Percent Area
   Statistics Type	Categorical	This ensures the values in each drought severity category are discrete rather than cumulative so that you can calculate a weighted sum for the Drought Severity Index.
   Location	Continental US (CONUS)	This tutorial focuses on mapping drought data in California, so we don't need to download data outside the continental US.

3. Click Submit.
   The file downloads to your computer.
4. Open the file to ensure it downloaded correctly and rename it us_drought_monitor.csv.

Next step

Download a California counties shapefile