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The StdConvert service acts as a filter for units, converting the unit system coming off your hardware to a target output unit system. All downstream services, including the archiving service, will then see this unit system. Hence, your data will be stored in the database using whatever unit system you specify here.

Once chosen, the unit system in the database cannot be changed!

WeeWX does not allow you to mix unit systems within the databases. You must choose a unit system and then stick with it. This means that users coming from wview (which uses US Customary) should not change the default setting. Having said this, there is a way of reconfiguring the database to use another unit system. See the section Changing the unit system in an existing database in the Customization Guide.


This service only affects the units used in the databases. In particular, it has nothing to do with what units are displayed in plots or files. Those units are specified in the skin configuration file, as described in the Customization Guide, under section Changing unit systems. Because of this, unless you have a special purpose application, there is really no good reason to change from the default, which is US.


If, despite these precautions, you do decide to change the units of data stored in the database, be sure to read the sections [StdCalibrate] and [StdQC], and change the units there as well!


Set to either US, METRICWX, or METRIC. The difference between METRICWX and METRIC is that the former uses mm instead of cm for rain, and m/s instead of km/hr for wind speed. See the reference section Units for the exact differences beween each of these options.

Default is US.