Stevenson Screen

http://www.loganvillageweather.com/station/stevenson.html
Having looked around at a number of different weather orientated website, and knowing that the best place for your outdoor sensor is away from objects that can affect the ambient temperature/humidity. The catch is that by having it out in the open, solar radiation (that big yellow thing in the sky) will naturally heat the outer surfaces of the sensor ultimately giving you temperature readings way off the planet, and possibly causing premature failure of the sensor.