[werk_ag]

If you had two options for the solar radiation shield and the temp /hum sensor position, would you put it up on the mast below the wind sensors, in the open weather and sun, or on the southern side (opposite side to the equator - Southern Hemisphere / Aust) of the house, on the wall, in the shade most of the time (approx 11 or 12m cable)..?

Whenever is possible the Rain Gauge and the Temperature / Humidity sensors should be placed at 1 to 2 meters above the ground level, and the Wind sensors around to 10 meters.
Avoid having the Temperature / Humidity sensor close to walls, or just above roofs. They should always have a good exposition to air flow from all directions.

The images below are from official weather stations, here in Portugal
I'm putting them just to illustrate the idea







As you can see the radiation shield and the Rain Gauge are always placed around 1 meter above the ground level.


If you are planning to use I2C sensors (SHT2x) with 10 to 11 meters cables it's better start to planning the use of I2C bus extender circuit. The TX boards already have a chip for this, but another chip should be used on the other end of the cable. Also the pull up resistors of the I2C extended bus should be carefully calculated, according to length and cable type (capacitance).
Preferably try to place the TX unit in a way that the longest cables are those for the anemometer / wind vane.

In some cases is more easy use one TX unit for the high level instruments (Wind speed and direction) and another TX unit for ground level instruments (Temp / Hum , Rain Gauge).