NEGAUNEE TOWNSHIP -- If you locate a thermometer near objects that give off heat, like metal and asphalt, it will likely give a hotter temperature. That's why both bank and car thermometers are almost always different from what the guy on the radio or TV says. It all depends on where you put them.
"Location, location, location; like real estate, temperature sensors are the same way," said Jason Alumbaugh, National Weather Service Meteorologist.
When measuring air temperature, keeping the thermometer protected from the elements is key. Moisture in the form of precipitation, like rain and snow, or condensation, like fog, will cause a colder reading from the instrument.
On the other hand, direct sunlight or proximity to objects that give off heat will cause a hotter reading.
At the National Weather Service, they specialize in taking air temperatures by following strict procedure.
"Usually the temperature sensor is inside what's called a beehive where you have that airflow moving through it," said Alumbaugh. "Because if you had a lot of still air just sitting there, it can get really hot very quickly. There's slits in there that allow the air to come and go through the sensor."
Guidelines also include placing it around five feet above the ground in a level, open, grassy area around 100 feet away from any paved or concrete surface. A full description of the National Weather Service Cooperative Observer Program can be found here: http://www.nws.noaa.gov/om/coop/standard.htm.
If you follow these standards, you could actually help the National Weather Service out by sharing your temperature and other weather data with them.
"We're definitely looking for more observations. So, if anybody wants to buy one of these home weather systems and put them up and then you can actually get that information; it's ingested into our models and it just makes us better forecasters in general," said Alumbaugh.
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