Daryl Ritchison, WDAY, Published March 29 2013
Weather Talk: Thermometer placement affects accuracy of tempsBank thermometers will often show erroneous temperatures. It is not so much that the sensor being used is inaccurate but, instead, the sensor is often placed in a poor position.
To accurately measure the air temperature, official thermometers have been placed in a white shelter box referred to as a Stevenson screen and more recently in a white enclosed ventilated plastic cover.
Often a thermometer used by a business is directly in the sun part of the day, plus the thermometers are often placed on roofs or near parking lots, which are dark and absorb much of the incoming solar radiation and make the surrounding air much warmer. That dark surface influence has been particularly noticeable in recent days as the strong early spring sunshine has a lot of potential to warm, but our snowpack has been limiting the area from reaching that potential.
So if you see a bank thermometer flashing 50 degrees on a sunny day, the reality is, it would likely really be 50 degrees if it was not for our deep snow cover.
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