Methods and related systems for measuring a temperature with an onboard sensor of a device of a heating, ventilation, and air conditioning (HVAC) system are disclosed. In an embodiment, the method includes (a) changing a power state of the device from off to on, and (b) detecting a raw temperature with the sensor after (a). In addition, the method includes (c) determining a time offset along a predetermined time and temperature relationship for the device, and (d) calculating a temperature offset with the predetermined time and temperature relationship at the time offset. Further, the method includes (e) subtracting the temperature offset from the raw temperature.