Bob wrote
Rod Speed wrote

What does work (but is expensive) is a solar powered vent
mounted on top of a 12" long piece of 6" ID PVC pipe

https://www.amazon.com/gp/product/B07LG4SSZH

That isnt very accurate at night.

Solar radiation is not a factor at night, numbnutz.

But lack of movement of the air is, ****wit.

Particularly when its all iced up in a heavy frost etc.