Our old basic kit that you link above has also temperature inaccuracies due to its small footprint but we have a new kit that addresses these issues and is also available as a pre-soldered version for easy assembly: https://www.airgradient.com/open-airgradient/instructions/di...
Something like: https://www.airgradient.com/open-airgradient/instructions/di...
I have bought all the parts, haven't had the time to assemble it yet.