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 30 automated weather stations located across Arizona supplies meteorological data (air and soil temperature, humidity, solar radiation, wind speed and direction, and precipitation) from important agricultural production areas and selected urban locations. A new station was installed in San Simon in 2011. 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 with 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; turf industry professionals may also 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 Prescott and Payson. A website 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. Demand for AZMET information remains high based on hits, sessions and data download. Phone calls, emails and face-to-face contacts indicate AZMET is viewed as a reliable source of meteorological data/information by a diverse clientele base. Demand for new weather stations remains high among rural clientele.

  • Users accessed AZMET web pages 1,870,000 times in 2011, and the total number of user sessions equaled 172,000, or 471 per day. The length of user sessions averaged about 15 minutes, while data transferred from AZMET’s websites totaled 328 gigabytes. 
  • Of particular importance are the evapotranspiration (ET) data generated for irrigation management and the Integrated Cotton Management Program (ICMP). Urban programs that utilize ET data include the web-based Phoenix and Tucson area turf water use reports, accessed 12,656 times in 2011 and the Northern Arizona Turf Water Use Webpage, accessed 4,606 times.
  • Rural programs using ET include the Southeast Arizona Crop Water Use Report and the Safford Cotton Water Use Report, accessed 840 times and 775 times respectively in 2011; cotton water use estimates, generated as part of the ICMP’s weekly distribution of planting date and crop development advisories for 15 locations throughout southern and western Arizona, accessed more than 19,980 times during 2011; and the 50,000+ acres of Arizona farmland now irrigated using ET-based scheduling systems.
  • The ICMP also uses AZMET data for online heat stress advisories that allow growers to monitor the impact of heat stress on boll retention. The heat stress reports were accessed approximately 9,500 times during the summer of 2011.
Conact Name: 
Paul W. Brown
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