I have the temperature reading calibrated with a function from: bme280-python/bme280/init.py
Also changed the bme280 to be forced mode as recommended.
My issue is that the rain gauge (reed switch) seems to be triggered randomly with absolutely zero rain. I’ve added ferrite beads (no help) and have switched back the the large USB wall wart for power which has seemed to help a little. I was getting a false reading every couple of hours now it is about one every 8 hours.
Not sure how to get the right setup to reduce the false readings. Seems like it has to do with how the Weather HAT is powered. Any help would be great.
Reference links.
Force Mode: Weatherhat onboard BME280, elevated readings, external I2C Option - #13 by ltoolio
False readings:
https://forum.sparkfun.com/viewtopic.php?f=74&p=247776&t=55474&sid=2a5d898a7e0c1ea7e03c4fcfa60319ae