U.S. Drought Monitor

 (data through 9/14/10)
Data Source(s): U.S. Department of Agriculture, National Drought Mitigation Center, National Oceanic and Atmospheric Administration

The extent of drought conditions across the western U.S. has not changed much in the past 30 days, according to the September 14 update of the U.S. Drought Monitor (Figure 3). Monsoon rains generally have been near average for the region, although there has been large spatial variability that has left some areas drier than others—a common occurrence during the monsoon. Northern and western Arizona are currently experiencing the brunt of the drought conditions in the region.

In other areas, dry conditions have plagued western Nevada and parts of northern California for most of the summer. Although these areas typically don’t experience much summer precipitation, less than 0.5 inches have fallen in many parts of this large region in the past 90 days. In the central Rockies, a dry spell has promoted the expansion of abnormally dry conditions over northern Colorado. Overall, approximately 27 percent of the West is classified with abnormally dry conditions or worse, just a 2 percent increase from one month ago.

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