Barometric Pressure not from my station?

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  • Updated 6 years ago
Hi,

I have just started playing with the API and am using $json_string = file_get_contents("http://api.wunderground.com/api/KEY/c...; and then parsing the data. When I do this the barometric pressure is not right. It doesn't match my weather station. It makes me wonder if the correct station is being queried. The other data seems to match but ...

thoughts

jeff
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jefflnester

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Posted 6 years ago

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John Celenza

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Hi,

The issue has to do with extra checks we perform through the API.

Barometric pressure changes very little over horizontal distances, so
there should only be a few hundredths (0.01-0.05 inch) difference between the
nearest airport and your weather station.

For instance, right now the airport nearby (KVJI) is:
30.04
while your station is:
29.85

That difference usually indicates that your barometric pressure is not calibrated to "sea-level pressure".

Most stations allow you to calibrate pressure. So, you could look at the pressure for KVJI (search that on wunderground), find the pressure, and set the pressure on your station to that value. Going forward, your pressure should be very close to the pressure at KVJI.

I hope this helps,
John
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jefflnester

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thanks! I have calibrated my station.

jeff