AZMET (Arizona Meteorological Network) is a network of weather stations that provides meteorological information for agricultural and horticultural use in central and southern Arizona. The network began operation in 1987 and now consists of over 25 stations. The stations monitor wind speed and direction, solar radiation, humidity, temperature (air and soil), and precipitation. Data from the network is posted to the AZMET website. Variables that are calculated using the weather data include potential evapotranspiration (ETo), chill hours, and heat units.