Waterproof your sensorbox
As your sensorbox will be outside, it's important to waterproof all the connections and sensitive electronics.
Hereafter, you will find an example of a waterproof system used without any greenhouse.
Use a plastic box to protect the solar panel
Use plastic bottles to protect the sensors
Put glue in every hole to insulate from water
Use a plastic box, some hooks, rope and tape ...
... to install the webcam