I've got a La Crosse Atomic Clock with the TX37U-IT outside sensor for temperature. The manual stated not to position it where it would get wet and the only place outside my apartment I could mount it was between the screen and window so I put it inside a freezer zip-lock bag.
I was apprehensive that condensation would form inside the bag and short it out but it's still going after 4 months and I haven't had to change the batteries yet. It has a readout for inside temp and humidity, moon phase, etc and is really nice.
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