What is ASHRAE weather data?

ASHRAE weather data provides standardized climate design conditions used by HVAC engineers to size heating and cooling equipment. The data is published in the ASHRAE Handbook of Fundamentals and includes design dry bulb and wet bulb temperatures at various percentiles, heating design temperatures, solar irradiance values, wind speed data, and monthly design day temperature profiles. Engineers use these values to calculate building heating and cooling loads at a specific location, ensuring that equipment is sized to handle the expected extreme weather conditions. Each weather station is identified by a WMO (World Meteorological Organization) number and provides data representative of the surrounding climate zone.