Arizona Meteorological Network (AZMET) Aids Crop Decisions

Research Year: 

Properly tailored weather information can assist with important management decisions related to variety selection, planting dates, crop assessment, pest control, irrigation and harvest, particularly during times of prolonged drought. The Arizona Meteorological Network (AZMET) was developed in 1987 to provide weather data and information in near real time to the state’s producers of agricultural and horticultural crops.

Description of Action: 

The AZMET network of 29 automated weather stations located across Arizona supplies meteorological data from important agricultural production areas and selected urban locations. Data obtained by the stations are transferred to a Tucson-based data processing center nightly, where computers process the data into a variety of informational formats to assist in decision making.

AZMET data and reports are available to the public free of charge via three Web pages. AZMET data provide reliable information on heat unit accumulation, used to monitor general crop development, to time planting and harvest dates for melons, sweet corn and other horticultural crops, and to predict pest development. For example, the AZMET Southeast Arizona Crop Water Use Advisory provides corn, forage, chile and nut growers in Cochise and Graham counties information on weather, water requirements and crop development. For cotton, AZMET generates weekly updates on heat unit accumulation, crop water use and current and projected weather conditions. The updates are distributed to nearly 500 growers each week as part of the Cotton Advisory Program. AZMET also provides daily updates on heat stress, which can significantly reduce cotton fruit retention and yield.

AZMET data on evapotranspiration (ET) are used to estimate the water use of vegetation, including field crops and turf. AZMET generates daily turf water use reports for the Phoenix area and distributes this information to the public via a turf water management web page and email; 39 turf industry professionals receive this information via email daily. AZMET also generates a lawn watering guide published daily in major and regional newspapers in the Phoenix metropolitan area. AZMET’s turf water management program includes weather stations in the low desert, and also in Flagstaff, Prescott and Payson. A Web site offers information on landscape irrigation to residents of northern Arizona. AZMET provides reference ET data to the Bureau of Reclamation for use in the Lower Colorado River Accounting System (LCRAS). LCRAS represents a new and improved means of assessing water use along this portion of the Colorado River.


AZMET is widely accepted as an important (and often the only) source of meteorological information pertaining to the production of agricultural and horticultural crops in Arizona. Use of AZMET information continues at a high rate; users accessed AZMET web pages 1,850,000 times in 2009. The total number of user sessions for AZMET equaled 255,470 in 2009, or 700 per day; data transferred from AZMET’s websites totaled 292 gigabytes.

Two examples of specific uses for AZMET data include evapotranspiration data generated for irrigation management and the Integrated Cotton Management program. Web-based Phoenix and Tucson area turf water use reports were accessed 8,100 times in 2009, the crop water report for southeastern Arizona was accessed 1,007 times, and the Northern Arizona Turf Water Use Webpage was accessed 4,000 times. In excess of 20,000 acres of farmland (cotton and alfalfa) in western Arizona are now irrigated with ET-based scheduling. As part of the Integrated Cotton Management program in Arizona, planting date and crop development advisories were produced for 15 locations from early March through the end of August. More than 9,000 reports were accessed from the AZMET site during this time; county faculty also distributed the advisories via hardcopy at a rate of about 500 per week. Online heat stress reports were accessed approximately 12,000 times during the summer of 2009.

Conact Name: 
Paul W. Brown
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