Effective distance is 600 feet in open air.
TO draw a graph you need only to sit at your reading room, turn on your air conditioning, look at the display set. You do not need to sit beside your smoker under wind, rain, snow, sun burning. But a graph does less help. In my Stumps type smoker, temperature fluctuation is + - 1 F.
But a graph of time vs voltage output and temperature may help you to fine tune P.I.D. parameters