Well, with a lot of help from my dad, I finally have a kind of Stevenson screen set up to house my automatic thermometer sensor, which is placed by the side of my back garden near a fence (and at the opposite side from the house). It is louvred at all four sides, and has a plain white top and bottom.
Some inflated readings while the sun was shining on the screen today that I might have to look into; don't know if the sun is somehow causing the screen to radiate heat despite it being 100% white, or if the sun shining on the solar panel has anything to do with it. Readings were fine after 2pm.
Hopefully, next summer it might mean not having to correct for inflated maxima due to warming from the hut, wall or various heat source that my thermometers were previously situated on.