Do you ask for a weather report in bad weather? If it says there is rain, but you can't see any, you have at least narrowed it down to being a hardware issue.
I don't see rain very often, but when I do, it usually increases to max after a while, and it becomes almost impossible to see clearly through it. And normally it's accompanied by heavy fog. This is not realistic, but I pretend that the report says 'poor visibility' instead, which makes it acceptable (maybe it's possible to hack the weather message?).
So you've actually been quite lucky so far, I think, if you've had no rain...
