The ambient data available under the Definitions branch come from the processing of measured data from ASHRAE Weather Data Viewer 5.0 (©2013 ASHRAE,
www.ashrae.org. Used with permission.), ASHRAE Weather Data Viewer 6.0 (©2017 ASHRAE,
www.ashrae.org. Used with permission.), and Weather Data Viewer 2021 (©2021 ASHRAE, www.ashrae.org. Used with permission.) given as frequencies of observations, monthly and hourly averaged for several past years of observation. They provide time-dependent weather conditions for about 8500 stations worldwide in terms of the dry bulb temperature, the dew-point temperature, the relative humidity, the wind speed, the absolute pressure, the precipitation rate, and the solar direct and diffuse irradiance.