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Weather Underground PWS IENGLAND56

Barometer Pressure

We were recently asked why the barometer pressure on the site was different to that on the archives, so here is an explanation.

The Raw Barometer value in the archive is the raw pressure recorded by the weather station.

The Sea level pressure on the display is calculated.

Since pressure changes with height (and temperature...) all stations correct their raw pressure to sea-level pressure in order to compare.

This is about 0.125mb/m.

CWS is ~13m above sea level so the corrected pressure is currently raw pressure + 2mb.

We have now added the calculated sea level barometer to the archive report as a comparison.


// CWS

Chester Weather Station (CWS) is run as an amateur weather station and therefore should not be used as official data.
Whilst every effort is made to keep the data as accurate as possible no guarantee is given that the data meets the requirements of the Meteorological Offices' 'A' Stations.
The weather station data is produced by CWS and CWS claims copyright over all data produced and disseminated by it.
Members of CWS may use the data produced by CWS for non-commercial use and no other purpose.
If CWS data is used according to these licence terms then the data must be acknowledged as belonging to CWS and reproduced with its permission.
The weather station data produced by CWS must not be used for decision making of any kind.
The weather station is privately owned and the owners do not make any claims as to the accuracy of the information collected by the equipment.