Barometric Pressure way off (corrected once CL system is deployed)

Sorry if this is not a new topic, but I looked through a number of threads and didn’t see it. I have only had my station up for 3 days, but the barometric pressure has been high the whole time. Currently, my two other consumer electronic stations (Rainwise and Bloomsky), along with my Chelsea analog barometer and the local airport are all reporting about 30.19. The Watherflow is reporting 30.297. Is there a way to adjust the BP offset?

Did you adjust your elevation ?

From the Webpage:
Make sure Elevation is correct for your location.

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Mine is running high also my elevation is correct according to google WF is 30.25 now trending rising Other station 29.57 manual good quality indoor unit 29.62 no complaint just stating a fact.

Yes, elevation is correct +/- about 10 feet.

EDIT - Now this is bizarre. The Weatherflow ap and website show BP at 30.82, but the Weather Underground page for this SAME station reports 30.22. Weird.

Could be a delay on updating on WU between WF

Yes, that must have been it, even though WU reported update times in the seconds. They are more in sync with each other (and not with my other instuments!) now.

Do yourself a favor and forget that Weather UnderWHO even exists! They do all kinds of silly things with PWS data, such as put their own calculated barometer values in place on a whim or make up solar/UV readings for stations that don’t even have the sensors to measure it…


I like WU. Sure it’s not perfect but for a free service I think it’s great. I like that I can visit one link and see tables and graphs of my weather history on one page. I like the ease of comparing my data to others locally, or great distances away. I also have a secret, guilty fondness for their overzealous snow predictions 10 days out!

Is the Air also in learning more to measure barometric pressure?

Mine is about 3 millibars to high in comparison to official stations and my Acurite station.

They measure 1027 mb and the Air says 1030 mb.

Not sure if it’s learning I’ve adjusted the hight of my location try negative values to get the hPa off mine was 4 hPa too high I made the station -8 m and now its fine compared to the nearest airport (Deelen)

Thnx! Will do that :hugs:

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Hi, I am new in here but find that the offset applied for altitude is not the measure shown in the app. I see 1019.5mb for pressure at sea level, and yet here where I live it says Station Pressure 1015mb, which is about right considering my altitude. So the app shows msl pressure and not station pressure isn’t that incorrect?

Yes, the applications show Sea Level pressure.


Gary, thanks for the information, I’ll have to ensure the TP app accommodates the difference.
Best Regards

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Keep in mind, the Smart Weather Station and the applications are meant for the lowest common consumer.

Hello @dorsetbred,

The Air unit reads station barometric pressure (of course). There are two places in the station and device management screens where adjustments in altitude can be made. When you setup your station, you picked a location which is converted into station elevation. In device managment, there is also a place to set the elevation above (or below) the station elevation. I find that with those two set correctly, both of my Air units read barometric pressure within a hundredth or two (in Hg) of each other and of the local NY State Mesonet station (and of my good old trusted mercury barometer). You can see both station pressure and sea level pressure in the current conditions screen. Just click on the icon in in the upper left corner of the main screen and the screen flips to the current conditions page.



There seems to be a few things cropping up that are becoming rather confusing. In simple terms, there should be sea level pressure and relative pressure. For example, I waited for a day of high pressure with very little change in trend before I adjusted the relative pressure on my Davis station, and that is the one that shows on the console, which has always been correct. I don’t understand why we must have ‘sea level pressure’ as one of the cards? I calibrated the WF to match the Davis station, but now knowing it is showing slp, the station’s pressure is incorrect. If I change the elevation to make it correct, the pressure on the card will be different, and that is wrong. Relative pressure should be the one in use, not sea level pressure - that is no good to me. Not only that, if I put in my correct elevation, and the elevation of Air, then the pressure reads some 4mb too high. This is exactly why relative pressure should be used because I am having to put in the settings that I live 30 feet below sea level, just to get the correct reading.

I adjusted my elevation down about 80’ and that got the Weather Flow station pretty much in line with my Rainwise and the local airport. I’m happy with that. It was interesting to see the difference even a few feet of elevation can make in the readings.

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80’ from what height?

We shouldn’t need to change any elevation settings to get a correct reading. Like the Davis’ stations, you input your height above sea level and then change the relative pressure to a steady value that can be obtained. Job done! Instead of that, I have to put in minus 32ft to get a reading anywhere near what is correct, and then it isn’t the stations pressure, it’s MSLP. It makes no sense.

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And I’ve now adjusted mine down so that it reads relative pressure as it was reading about 3mb too high. Apologies for wasting peoples time.

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