The Xiaomi Aqara Temperature and Humidity sensor monitors temperature, humidity, and atmospheric pressure in real time. It uses the Zigbee protocol and is compatible with Mi Home, Apple Homekit, Alexa, Homey, Home Assistant and Domoticz. The sensor is small and cheap compared with other sensors.
The digital temperature sensor DS18B20 manufactured by Maxim Integrated (formerly named Dallas Semiconductor) can measure temperatures in the range -55 °C to + 125 °C, with a accuracy varying between ±0.5°C and ±2°C depending on the subrange in which is measured. It works via the 1-Wire protocol and as such can be easily connected to Arduino boards.