Most turbo installations have a wastegate, which regulates the pressure of air sent to the intake [by adjusting the amount of exhaust that feeds the turbo compressor drive]. Some (few) of them are simple "pop offs", which dump a lot of pressure by opening and venting to the atmosphere in a condition of excess pressure. Others (more) are variable, attempting to target a maximum pressure.
I have a lot of data logs from my airplane installation. Figures vary greatly based on outside air temp and altitude (turbo "works harder" in thinner air), but some typical figures with intercooler are:
CDT : 230°F
IAT : 90°F
OAT : 40°F
where CDT is compressor discharge temp (post-turbo, pre-intercooler), IAT is intake air temp (post-intercooler), and OAT is outside air temp (ambient, and the heat sink temp for the air-to-air intercooler).
In this system, a variable wastegate attempts to keep the manifold pressure at full throttle at 30.0 inHg absolute, meaning the lower air temp is linearly related to more mass air flow into the engine (when expressed in Kelvin/Rankine terms). Here are sample IAT plots comparing intercooled vs non-intercooled applications.
Car turbos are typically designed to boost above ambient and if a car gets to 20K MSL, something has gone terribly wrong, of course...but the physics of induction temp are the same.