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.) and ASHRAE Weather Data Viewer 6.0 (©2017 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 more than 8000 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.