It is mostly the dark current (which is reflected in the values you would get if no light is hitting the CMOS sensor) which is affected by temperature. However, its effect scales with the exposure time. Since night time astrophotography requires long exposure times, this would require recalibration (see also @bdigiifh's post). However, for typical daytime use the effect is much less significant.
Some CMOS sensors or the surrounding electronics components on the PCB can heat up significantly while the sensor is in use.
If the sensor has a configurable gain (which is the hardware amplification applied before digitizing the voltage measured for each pixel), then you probably want to characterize the pixel-to-pixel variation for each gain level.
In professional astronomy (where sensors are kept in dewars to reduce dark current) this process (flat field, dark field) is carried out at least once a night.
Some CMOS sensors or the surrounding electronics components on the PCB can heat up significantly while the sensor is in use.
If the sensor has a configurable gain (which is the hardware amplification applied before digitizing the voltage measured for each pixel), then you probably want to characterize the pixel-to-pixel variation for each gain level.