What do all the calculated (derived) variables mean? How do I use them?

  • Your Davis weather system has a number of sensors that collect data, such as wind speed, temperature, and humidity. As well as this data, your system will calculate other variables, using the true data and a series of calculations
  • Check out our info sheet ‘Weather Station Variables’ on our Resources page to see a comprehensive list of measurements and derived variables that Davis systems are capable of

Examples of derived variables include:

  • Heat Index and Temperature Humidity Sun Wind (THSW) Index: Useful when thinking about the impact of the weather on people or animals, such as overheating, wind chill and dehydration
  • Potential Evapotranspiration (ET) Rate: Useful when monitoring plant growth and water usage, such as irrigation
  • Wet Bulb Temperature (Delta-T): Used when spraying to select the best conditions to maximise spray coverage