My niece, Miss V, is staying with us for the summer again, and we are really happy to have her here with us. But since she switched from an outside temperature in the 80s-90s to the Northwest’s 60s-70s — and not to mention the really dry air on the plane — she has come down with the sniffles and sore throat.

Last night, being sure she was running a temperature, she asked me to break out the thermometer and check. Four minutes later, the thermometer showed she had a normal temperature, but we explained that people can still be sick without running a fever.

V patiently held the thermometer under her tongue, but an oral thermometer is not the only way to take someone’s temperature. There’s always the rectal thermometer, but that’s just grody. I remember occasionally being dropped off at a day care facility in North Dakota as a kid, and the people there would take our temperature with a sensor held under the arm. This was faster than an oral thermometer, and it didn’t require the sterilization like something used orally. My favorite method remains the thermometer used in doctors’ offices that takes your temperature from your ear drum. It’s fast, can’t be spoofed with a hot drink like an oral thermometer can, and it doesn’t have the oogie factor of a rectal one. *shudder*

When you get down to it, what exactly is a person’s temperature? The hands and feet tend to be colder than the trunk, and the temperature of the skin outside is lower than the gooey bits inside. And to make matters even more confusing, a body’s internal temperature rises and falls during a 24-hour period. So what is the “normal” temperature for a person? Do we average a person’s temperature or add the top and bottom temperatures together and divide by two?

If the matter of someone’s temperature is this complicated, how much more complicated is taking the temperature of the planet? Scientists say that the temperature of the planet is going up, but how exactly do they know this? How exactly do you tell the Earth to open up and say, “Ahhhh”? And where do you stick the thermometer? I am confident that smart people have considered matters like seasons, time, location, and local weather in their global calculations, but I doubt they have taken everything into consideration.

I say this because Anthony Watts of Watts Up With That? blog is doing some very interesting work looking at the location and conditions of weather stations in California. Weather stations that had been for years in rural areas are suffering from urban sprawl. And as buildings and blacktop surround these weather stations, it’s no wonder that the temperatures recorded are going up. These stations are measuring the effect of the urban heat island that surrounds our cities. Asphalt roads heat up more than a similar area of grass and greenery. Buildings can block the wind and reflect the sun back onto the weather station. Heck, even the use of latex paint instead of whitewash on the weather stations themselves could have a non-subtle effect.

Watt’s work on looking at the weather stations is very interesting to me, mainly because he has shown some rather bad set-ups. Below is a picture taken from Watt’s site showing the weather station in Forest Grove, Oregon. Notice that a significant heat source, the air conditioner, is situated right next to the weather station.

Forest Grove weather station

What is less obvious from that photo is the encroachment of buildings and roads around the weather station. I find that this weather station could be affected by the urban heat island that has built around it. Watt makes a guess that the AC box was installed in 1985 because the Forest Grove data shows a jump in temperature that year, and it has stayed at a higher temperature plateau ever since.

Watt also compares the temperature readings of Marysville, CA with the weather station in Orlando, just 50 miles away. The Marysville annual mean temperature plot shows a steady increase in temperature over the years, but Orlando’s data does not. The difference being Orlando remains in a rural area, and the Marysville weather station is surrounded by a fire station, with AC units, concrete, reflections, and the firefighters’ BBQ.

Do these examples mean that all temperature readings for the past few decades should be shoved out the window? Well no, but we certainly need to examine our method of recording these temperatures. We don’t want to judge the temperature of the world if these weather stations are doing the equivalent of children taking a really hot drink before sticking the thermometer under their tongue.

“I’m sorry, Son. You can’t go to school today with a temperature of 127°.”

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