[Ductapemaster]

Jose - I have done a few designs for my current employer using the BME280 for environmental sensing. I've found it a little sensitive to heat, both from the environment and itself. There's a good resource from K&R Smith[1] about comparing the sensor to others and there's some discussion about how to set up the sensor to minimize self-heating. Might be worth looking into!

Additionally, when I do my designs, I place the BME280 sensor as far away from other components as possible (I see it is close to a SOIC chip on your board) and I route a cutout in the board around the sensor to reduce any heat conduction from the board. I also ensure that I have no power planes on the little resulting "island" PCB, and use small traces (with local decoupling) to further reduce any conductive heat. See the image in [2] for an example of what I am talking about.

Another alternative I pursued in situations where convective heat was an issue is to stick the sensor on a little remote board and use an off-the-shelf wire to connect the two (check out the Sparkfun Qwiic wires[3])

Overall you want to increase airflow around the sensor as much as possible so leaving it "hanging out" somewhere is the best approach to getting accurate measurements.

I hope that helps!

[1] http://www.kandrsmith.org/RJS/Misc/Hygrometers/calib_many.ht...

[2] https://www.instructables.com/id/How-to-Measure-Temperature-...

[3] https://www.sparkfun.com/products/14427