There are a couple of touchpoints you'd want to take a look at:

ISO 9806:2017 Solar energy — Solar thermal collectors — Test methods and

IEC 61853-1:2011 Photovoltaic (PV) module performance testing and energy rating - Part 1: Irradiance and temperature performance measurements and power rating

They will both give you a sense of the temperature rise given a ambient air temperature, wind speed and plane of array irradiance.