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I just purchased a wireless weather station, and the barometric pressure reads 24.36 in Hg. Is this correct, I always thought it should be around 29 to 30. I live in Coalville Utah, rather than salt lake, but should it change in elevation? What is the average pressure in Coalville?
Kim B.
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Oh no it's constant low pressure over Coalville! Just kidding! What you're seeing with those 24 type of numbers is the barometer reading which has not been adjusted to sea level. Pressure drops as you climb higher in the atmosphere, so if we used true station pressure all the time, we'd always have lower pressure at higher elevations. Since that would not help us in our map analysis at all, we adjust the pressure accordingly.
So you are right, your barometer should not read 24 at all, most pressure readings are in that 29 or 30 ballpark.
There may be a function in your barometer where you can change the elevation, you might want to read the manual. You can also use a reading from another barometer nearby that is already calibrated, but your best bet is to change the elevation inside of yours. You can find a local weather station probably at wunderground.com and type in your city name and state, hopefully you'll find one nearby.
To get your new pressure that is adjusted to seal level in Coalville, you'll need your temperature, elevation above sea level and the barometer reading. You'd use a complicated equation for all of that so you'd be better of trying to get a barometer that is already adjusted nearby. You can also add around 1 inch of mercury for every 1000 feet you are above sea level.
Look for a local weather station also on the Utah Mesonet, the link is on the right. When you load the page under "settings" you will want to view "all networks" and find a close by location by county. Not all of the stations have barometers though but it's a good start.
Answered by KSL Meteorologist Dina Freedman
