Placing the Thermometers

This Internet rumor is just credible enough that I'd like to talk about it: "Last summer only seemed to be so hot, because weather stations have been encouraged to put their thermometers and other measuring devices in hot spots, near the heat pumps at the back of the building or on a patch of unshaded pavement in the parking lot, to make some version of global warming theory sound more convincing."

It's happened. Weather stations are supposed to measure temperature in a shady spot but some digital thermometers, with their own little shades, have been installed in places where the temperature is closer to what it is for people waiting for a crosstown bus, downtown. 

And this really does matter, because even in a small city--e.g. Kingsport, Tennessee, population about 55,000--the difference between the official weather station temperature, as measured in the shade near a stream, and the temperatures on banks' thermometers downtown, can be twenty degrees Fahrenheit. 

When I've blogged about the difference in temperatures between downtown Kingsport and the Cat Sanctuary I'm not talking about the weather station temperatures, which haven't changed much. I'm talking about the ovenlike quality of even the high-traffic suburban shopping streets outside the city limits. 

You can test this at home if you have a few different thermometers. 

* Place one thermometer in the shade, the other in the sun. In some parts of the Western States there's not much shade anywhere, but in the East, rural tends to mean shady and downtown tends to mean unshaded.

* Pick a day when the outdoor temperature is bearable and measure the temperature near a heat pump when it's not blowing out hot air. Then measure the temperature over the next few hours after the air conditioning is activated and the heat pump is blowing out hot air.

* Measure the temperature with a shaded thermometer fastened to a post about four feet above pavement, and one fastened to a post about four feet above grass. 

* Measure the temperature inside and outside a parked car.

* Measure the temperature in a booth at a crowded street festival, and the temperature in an empty lot a couple of blocks away. 

* Measure the temperature in a room with a big window that faces south or west, and a room with a small window that faces north.

* Measure the temperature as high up the wall as you can reach, and down along a baseboard on the same wall.

The differences in readings will vary from day to day because of wind, clouds, and humidity, but one of each pair of locations will consistently show a higher temperature than the other.

Have unscrupulous weather reporters really been giving you temperature readings that you believe are accurate because that's what the bank sign at the bus said too, comparing those readings with readings from a shady spot beside the lake, and telling you, "Wow! Temperatures are much higher than they were ten years ago! That's because of global warming!"? If so, documenting inaccurately gathered and reported data would be useful to science. There's no need to make a big issue of it. Most people don't realize how different temperature readings can be, 

Where thermometers are placed does not prove or disprove any global warming theory, but this information about the local warming effects on your home can help you decorate (or move!) in ways that reduce your heating and cooling bill.