I'm planning to do a sump pump depth gauge too at some point as an emergency "pump is busted!" alarm - very interested if you don't mind sharing your thoughts for that design.
The measurement of percent humidity is dependent on temperature - cold air can hold less moisture. For the same moisture content, the lower temperature will have a higher percentage of its capacity. If you want a measure that is independent of temperature, look into something like Dew Point.
Passed this on a backpacking trip in the Berkshires, northeast US. Very new to mushroom ID, but iNaturalist said it was Chicken of the Woods! Didn't try to eat it, but it was cool to find something potentially edible! I later spotted a ton more on fallen trees farther off trail.
Try some tea! Camellia sinensis
Mine is a little over a year and a half old, and it just flowered for the first time! I have made 1 (one) cup of tea from it so far (: