Like David, I have an "atomic" clock with an in/out temp and humidity monitor (LaCrosse I think). I've had Oregon Scientific brand in the house, but recently they've gone to a screen product line-wide that is too dark for us to make out the digits on, so I won't buy their stuff anymore.
To get the outside remote sensor to a neutral position where direct sun or rain would affect it or its readings, I fastened it, via velcro I think, to the top of a frame brace alongside the genset. It's easy to get at for battery changes, is reading mostly shaded ambient air, and is protected from most harm. I don't really have the base unit where it's visible while driving because I use the Aladdin for that, but while camped it is handy to have on the buffet or a wall. The only minus is you obviously can't rely on the outside reading while the generator is in use and warmed up, but for us that is pretty infrequent anyway.
Joel