Weatherhat humidity calibration?

Hello,
I have a weatherhat on a Pi 3 A+ and its working fine except the humidity is very low. Using the OFFSET variable in the example python scripts I can get an accurate temperature reading but not an accurate relative humidity. Can the humidity readings be adjusted in the scripts or the in the python library (which I assume is the pimoroni-bme280)? Any pointers in the right direction will be appreciated.
Thanks.