Circuits and methods for extending the linear range of IC-based environmental sensors. The IC-based environmental sensors may sense environmental characteristic such as humidity levels, the presence and/or concentration of specific chemicals, and/or the presence and/or concentration of specific biological molecules. The linearity of an environmental sensor can be extended by heating the sensor within a range of non-linear operation to artificially induce the sensor to operate within its linear range, and then accurately measuring, either directly or indirectly, the temperature rise caused by such heating. A correction factor is then determined based on the measured temperature rise that is combined with measurements from the sensor while operating within its non-linear range in order to generate an accurate estimate of an actual environmental characteristic.