WRAL WeatherCenter Blog

If the thermometers we have around the house, inside and outside, show significant above temps that the "official" thermometer at the airport does, witch really reflects what humans feel? i.e., I'm sitting under a shade tree with my new thermometer next to me, it reads 112F. Why should I feel cooler because the NWS broadcast a temp of 102f?

Posted August 11, 2007

MIKE MOSS SAYS:      Bruce,     How a person feels at any given location certainly depends on the air temperature at that location, not to mention on how they are dressed, whether the wind is blowing at that spot and how fast, and the degree to which they are exposed to direct sunlight. Variations in elevation, cloud thickness, land-use characteristics, precipitation distribution and the presence of frontal boundaries are all additional reasons that temperature can vary significantly over a fairly short distance. If your thermometer is accurately calibrated, properly ventilated and shielded from direct radiation (from the sun of course, but also from cars, houses, commercial facilities and the like off to the side that may be in direct sunlight themselves) and it gives an air temperature reading of 112F, then you may simply be in a really hot spot. There are plenty of those around, usually associated with large areas of pavement nearby, like four lane roadways, commercial parking lots and so on. There can also be a notable vertical gradient of temperature from the ground surface up into the air, so a themometer at six inches or a foot off the ground might yield a reading several degrees warmer (daytime) or colder (calm, clear night) than an "official" reading taken about 4-5 feet above the ground.


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