"Hot Day", "Tropical Day", "Standard Day", "Polar Day" and "Cold Day" are part of the lexicon of the aircraft industry. These terms are generally understood to refer to specific, generally accepted characteristics of atmospheric temperature versus pressure altitude. There are also other, less well-known days, defined by their frequency of occurrence, such as "1% Hot Day", "10% Cold Day", or "Highest Recorded Day". These temperature characteristics have their origins in multiple sources, including U.S. military specifications which are no longer in force. This document is intended to preserve the commonly used day types in an accessible form for future use, make recommendations for their consistent usage, and collect the data in a single format.
SAE ARP210-2007 history
2014SAE ARP210A-2014 Definition of Commonly Used Day Types (Atmospheric Ambient Temperature Characteristics Versus Pressure Altitude)
2011SAE ARP210-2011 Definition of Commonly Used Day Types (Atmospheric Ambient Temperature Characteristics Versus Pressure Altitude)
2007SAE ARP210-2007 Definition of Commonly Used Day Types (Atmospheric Ambient Temperature Characteristics Versus Pressure Altitude)