Questions about measuring pool and spa temperature show up here with assorted solutions. Most of these seem best suited for more advanced users or require more expensive components.
Here is a "quick and dirty" solution I set up yesterday. It uses a Samsung temperature/motion sensor - or clone - and a random bolt and the vacuum sealer. I sealed the Samsung in its own pouch (no vacuum) with double seals. I put the Samsung pouch at one end and the bolt at the other end and sealed in a second pouch about 12 inches long.
The Samsung was already connected to my C8 and remained connected when I dropped it in the spa. The bolt keeps it upright and floating with 10% to 20% just at the water level and the rest submerged.
The display is from SharpTools and I also have an Echo Speaks announcement at 100 degrees.
It remains to be seen how long the Samsung remains dry.
Ya i would have out it up but didnt find it on amazon. Benefits you an add 16 more temp sensors and leak sensors and air quality later all without the actual weather station.
I am not sure of long term reliabilty of the
floating sensor as it has not been out long and battery is not replaceable.