This isn't a plain outdoor thermometer - it has a range of -50 to 600°C.
When you want to measure extreme temperatures, the go-to tool is a thermocouple, which is a junction between two different metals. The way these metals change conductivity through changing temperatures lets you measure wide temperature ranges. The trouble in using them is that you need to carefully amplify the signal.
The Grove Temperature Sensor features a "K" type unit, with a detectable range of -50 to + 600°C , with accuracy is ±(2.0% + 2°C)