Wonder if this is actually modeled...Kinda doubt it...
Yes, the outside air temperature can affect the accuracy of a suction gauge:
Temperature range shift: The elasticity modulus of the gauge's bourdon changes with temperature, which can cause a shift in the zero set point. This shift can be as much as 1% for every few degrees of temperature change.
Zero shift: The physical dimensions of the gauge's components change with temperature, which can cause a zero shift. This shift is constant across the entire scale.
Discoloration: High temperatures can cause the gauge dial to discolor.
Hardening: High temperatures can cause the gauge's gasket or seal to harden.
Liquid expansion: If the gauge has a liquid-filled case, the case fill fluid will expand with temperature.
Other factors that can impact the accuracy of a vacuum gauge include: Pulsing, Vibrations, Gas type, and Operating pressure range.