The HDC1050 from Texas Instruments is a tiny 3 mm square combined humidity and temperature sensor. It can operate from a supply rail of 3 to 5 V and offers an accuracy of ±3 % on relative humidity measurement and ±0.2 ºC on temperature measurements. The typical supply current is 1.2 µA while operating at one sample per second and 100 nA in sleep mode.
HDC1050 – low power Humidity and Temperature sensor – [Link]
