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Published August 25, 2010
Data Source(s): High Plains Regional Climate Center
Precipitation since the water year began on October 1 has been patchy across most of Arizona and western and northern New Mexico (Figures 2a–b). The higher elevations of southeastern and northern Arizona and southwestern and the eastern half of New Mexico have been much wetter than average, with average precipitation ranging between 100 and 150 percent. A few isolated locations in New Mexico and the southwest corner of Arizona have received between 150 to 300 percent of average precipitation, including the lower Colorado River Valley on the western Arizona border. However, during the summer and particularly the past month, the lower Colorado River Valley has been quite dry.
During the last 30 days, the northeast corner of Arizona in the Virgin River watershed has been extremely wet, as has the Colorado Plateau and the eastern half of Arizona and northwestern New Mexico (Figures 2c–d). On the other hand, most of southern New Mexico has been very dry in the past month, receiving less than 70 percent of average precipitation. Summer precipitation is typically quite isolated and the recent wet conditions in southeastern Arizona are helping to make up the winter deficit of precipitation in this region. Unfortunately, the rainfall deficit in south-central New Mexico is continuing to grow as the monsoon activity remains to the west along the Arizona-New Mexico border.Notes:
The water year begins on October 1 and ends on September 30 of the following year. As of October 1, 2009, we are in the 2010 water year. The water year is a more hydrologically sound measure of climate and hydrological activity than is the standard calendar year.
Average refers to the arithmetic mean of annual data from 1971–2000. Percent of average precipitation is calculated by taking the ratio of current to average precipitation and multiplying by 100.
The continuous color maps (Figures 2a, 2c) are derived by taking measurements at individual meteorological stations and mathematically interpolating (estimating) values between known data points. Interpolation procedures can cause aberrant values in data-sparse regions.
The dots in Figures 2b and 2d show data values for individual meteorological stations.
For these and other precipitation maps, visit:
For National Climatic Data Center monthly precipitation and drought reports for Arizona, New Mexico, and the Southwest region, visit:
Southwest Climate Outlook Staff
- Michael Crimmins, UA Extension Specialist
- Stephanie Doster, Institute of the Environment Editor
- Dan Ferguson, CLIMAS Program Director
- Gregg Garfin, Founding Editor, Institute of the Environment
- Zack Guido, CLIMAS Associate Staff Scientist
- Gigi Owen, CLIMAS Assistant Staff Scientist
- Nancy J. Selover, Arizona State Climatologist
- Jessica Swetish, CLIMAS Publications Assistant
Please direct your Southwest Climate Outlook comments and suggestions to Zack Guido.
The CLIMAS Web site contains official and non-official forecasts, as well as other information. While we make every effort to verify this information, please understand that we do not warrant the accuracy of any of these materials.... Read full disclaimer