Hey Ray: Why is my temperature at home different than what's on TV?
PITTSBURGH (KDKA) - I get asked frequently why someone's thermometer reads differently than what we show on TV and online. There are a couple of reasons for the differences.
The first is the thermometer on someone's back porch compared to the precision instruments used at official weather reporting stations.
While you might not have the fanciest thermometer, that is okay! You can still get a good reading from it.
You may, however, still be doing some things incorrectly.
The next reason there may be a big difference in temperature readings is where you place the thermometer.
To realize why placement is so important you have to realize that the sun heats the ground which, in turn, heats the air.
First off, if your thermometer is in direct sunlight, your readings will be way off. You will want a shady spot, but not near your house.
Official weather stations are placed four and a half feet to six feet off the ground and over a grassy location that allows wind to freely pass through.
So, if your thermometer is on the back porch, you are likely reading some of the heat coming off the porch and off of your house.
Who knew thermometer placement had so many rules?
To get all these things right, the National Weather Service uses a weather instrument shelter.
This keeps the thermometer sheltered.
It allows air to freely pass through, and it is white, which reflects the sunlight to prevent it from warming up.
This is likely why car thermometers always seem off.
Cars are not usually 4.5 to 6' off the ground. They drive over pavement, which absorbs then radiates a ton of heat, and the car itself can become hot to the touch in direct sunlight, impacting the temperature reading.
It gives you an idea, though, so they are still nice to have!