Temperature sensor that is reliable?

I think history has shown us that there isn’t anything that can operate “consistently and reliably” on SmartThings. The platform itself is unstable. As the company says in their official product usage guidelines:

https://www.smartthings.com/guidelines

Data accuracy and consistency from SmartThings sensors, including those provided by SmartThings directly, resold by SmartThings, or supported by SmartThings, is not guaranteed. Therefore, you should not rely on that data for any use that impacts health, safety, security, property or financial interests. For example, because temperature readings may vary significantly from reading to reading on an individual device, between devices, or over time, those readings should not be used to control heating and cooling in environments where food spoilage, health risks, or damage to physical goods could occur.

That said, I think people have had better luck with the purposebuilt temperature monitors, rather than the ones built into the other sensors.

I don’t think much has changed since the following thread