Perhaps the most widely used drought status assessment is produced by the U.S. Drought Monitor (USDM; Figure 1). The USDM is a weekly synthesis of many types of climate information, including precipitation, snow, temperature, impact reports, and expert assessments made by scientists. The USDM focuses on broad-scale conditions which may differ from local conditions.
For each state and region, the USDM tabulates the percent area affected by different drought statuses and compares the current conditions to previous weeks, months, and specific dates. For Arizona, the Arizona Drought Monitoring Technical Committee helps define the drought classification in the state. The USDM is housed on the National Integrated Drought Information System (NIDIS) Web site.