The DS18B20 compatible temperature sensor is a reliable and cheap way to add temperature monitoring to your Arduino, ESP8226, or ESP32 based project. There are various libraries available for the Arduino and Micropython environments. Best of all, these 1-Wire sensors only take up 1 GPIO for the signal which makes them super easy to wire up.
Each sensor comes with a unique serial number flashed in so you can have dozens of them all on the same 1-Wire data line. These are also useful for embedding in projects like object trackers as each one has a unique serial number.
Range: -55°C to 125°C
Don't forget the 4.7kOhm pull-up resistor on the data line. Your sensor(s) won't work without it!