This is a Stevenson Screen, a type of housing for weather stations to protect from wind, rain and sun to monitor pressure and temperature more accurately.   It is designed for the SwitchBot sensor, available on Amazon.

What makes this better than other Stevenson Screens?

This does follow the description of what a Stevenson Screen is supposed to have.   It doesn't just look like one on the outside, it has the requirements fulfilled.

Double Louvred sides.   There's angled rings inside and outside, to deflect rain from entering, and also drip away from the sensors.    Even though the SwitchBot sensor is rated for outdoor use, it is better to keep it dry and therefore more accurate.

Double layered roof.   To prevent the sensors being heated by sunlight, it should have a double layered roof with an air gap.   Unlike others this provides this layer.

The base of the Stevenson Screen is open to the elements, as required.

Improvements to other designs.   One of the problems with other designs is the need to source very long screws to reach the full height of the screen.   In my design you offset each layer alternatively and use short screws to assemble the screen.

Access to sensor through base.   You can remove the sensor without disassembly through the base of the unit.   The sensor is clipped in place and held sufficiently.

Alternative sensors could be used inside the Stevenson Screen by simply changing the design of the final holder as it is only screwed onto the base.   Minimal work would be required to adapt this to another type of sensor.

For the internal screws I used self tapping 3mmx10 screws from Farnell, order code 2474971.   To mount the sensor cage I used M3x12mm screws (2770719) and their respective nuts (3755163) and washers (1377496).   To mount the whole Stevenson Screen I used generic wood screws.