La Crosse Technology Weather Station Instruction Manual page 25

Note: Units of weather icon sensitivity and air pressure history are not affected. They are always expressed in hPa.
RELATIVE AIR PRESSURE VALUE SETTING
The default relative pressure value is 1013 hPa (29.92 inHg). This can be manually set to another value within the
range of 960 – 1040 hPa (28.35 – 30.72 inHg) for a better reference.
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