I designed this stand for my 2 thermometer and hygrometer, that I bought in an electronic store (I published the link in the notes below).
Since this is a standard part, I decided to share this model, so it can help others.
The thermometers have a clamp that snaps in the holder, so no screws or glue are required.
Here are the thermometer dimensions:

 - Dimension: approx. 48 x 28.5 x 15.2mm - LCD Dimension: approx. 40 x 22.5mm - Installation dimensions: approx. 46 x 27 x 13.5mm

Hope you all appreciate it.