Grove Temperature & Humidity Sensor - 

The Grove temperature and humidity sensor (SHT31) could be the finest and highest-accuracy humidity sensor you can find, as it can acquire the relative humidity at only ±2% error. On the other side, it also features excellent performance in terms of temperature measurement, you can use it in some extreme conditions, like -40 degrees or 125 degrees, and it still keeps an accuracy of ±0.3 degrees.