Stacking more systems into a compact area or scaling devices to increase the density of integration are two approaches to provide greater functional complexity. Excessive heat generated as a result of these technology advancements leads to an increase in leakage power and degradation in system reliability. Hence, a thermal aware system composed of hundreds of distributed thermal sensor nodes is needed. Such a system requires an efficient thermal sensor placed close to the thermal hotspots, small in size, fast response, and CMOS compatible. In this paper, two hybrid spintronic/CMOS circuits are proposed. These circuits exhibit a low power consumption of 11.9 $\mu$W during the on-state, a linearity ($R^2$) of 0.96 over the industrial temperature range of operation (-40 to 125)$^oC$, and a sensitivity of 3.78 mV/K.