Resistance thermometry is a time-tested method for taking temperature measurements. In recent years, fundamental limits to resistance-based approaches have spurred considerable interest in developing photonic temperature sensors as a viable alternative. In this study, we demonstrate that our photonic thermometer, which consists of a silicon waveguide integrated with a Bragg grating, can be used to measure temperature changes over the range of 5 degrees C-160 degrees C, with a combined expanded uncertainty [k = 2, 95% confidence level] of 1.25 degrees C. Computational modeling of the sensor predicts the resonance wavelength and effective refractive index within 4% of the measured value.