A high-performance temperature sensor based on a p-GaN/AlGaN/GaN hybrid anode diode (HPT-HAD) fabricated by hydrogen plasma treatment is demonstrated. The sensor exhibits accurate and stable temperature responses from 73 to 573 K. The forward anode voltage is linearly proportional to the temperature over the measured temperature range at a fixed current. At a forward current density of 10−7 mA/mm, the device achieves a maximum sensitivity of 1.93 mV/K. The long-time anode current stress measurement reveals that the HPT-HAD shows almost no degradation even at 573 K for 1 h at a current of 100 μA, and the anode voltage shifts only 120 mV at 573 K for 1000 s at 1 nA. This work shows that the HPT-HAD temperature sensor can be reliably operated over a wide temperature range from cryogenic to high temperatures, so can be used in a variety of extreme environments.