During the “winter”, sure, but it dumps rain during the same and there are flash floods occasionally. I agree with the parent comment that Miami is a great area to test - especially given that the bad weather is seasonal. They can run 24/7 during the good weather seasons.
Also, the drivers in Miami are a bit more unpredictable than the average driver around the country in my experience, so good challenge cases for self-driving development.
Unpredictable drivers aren’t a challenge compared to weather. They’re just 3D objects to avoid. That’s a solved problem.
The thing about weather is that with a fully automated fleet they can just stop and give up on driving instantly. Rain in Miami doesn’t tend to last very long except in specific storms like hurricanes. Waymo can just not operate during those times.
I’m very doubtful that a lot of these inherent problems with the technology are being rapidly solved. See: the article.