The Arduino Nano, when paired with a waterproof temperature sensor module like DS18B20, accurately measures temperature in liquids or harsh environments, suitable for applications in aquariums, ...

The other wire goes to PIN 10 of the Arduino board and also to a 4.7k Ohms resistor which other end is connected to 5 Volts. The OLED screen has 4 PINs: GND pin to ground, VCC to 5V, the SDA PIN is ...

If you're purchased a waterproof temperature sensor online, it's likely a fake DS18B20 chip with possibly poor accuracy, lacking EEPROM and out of specs.