You may want to read this from
Ambient Weather before applying Rain-X, Hendlex, and other car care products to your Ambient Weather devices:
How do I prevent snow build up on my weather station?
Snow build up is difficult to prevent, especially “wet snow”. You can spray the top of the unit with teflon snow and ice repellent like this:
https://www.amazon.com/DuPont-Teflon-Snow-Repellant-10-Ounce/dp/B0031T82NO
but this is not 100% effective.
Snow is considered normal maintenance, and accumulated snow can be brushed off gently with a broom.
I sprayed a fairly good coat of the DuPont Teflon spray onto my WS-2902A sensor array before installing it on its 10' high tilting mast the day after Christmas. While I considered masking off the solar panel and UV sensor, I didn't bother after testing the spray on other objects including the several snow shovels, the snow blower, and the rain gauge funnel. In all cases, it remained clear, and with a dull glossy finish. Below is what the unit looked like after receiving a coat of the snow and ice repellent.
[ You are not allowed to view attachments ]
Since then, we've had a number of snow events. The first snow event shortly after Christmas was a wet sticky snow through the night. At about 4:00 AM, the anemometer stopped, but wasn't noticed until about 4:45 when I went out and simply tapped the mast a few times until enough snow fell off freeing the wind cups to begin spinning again. None of the other snow events since have resulted in the anemometer stopping, nor has there ever been any noticed reduction on the radio signal strength from the outdoor sensor array located about 80' from the Console Display. The last major snow event began late on the 19th and ended early AM on the 21st with very cold temps, blustery winds and a very dense type of snow, none of which stuck to the sensor array.
[ You are not allowed to view attachments ]
Of course, there's plenty of Maine winter left to come, and I may have to lower the mast to clean off the sensor array, but so far it hasn't been needed.