When you join a server, you will be able to see everything clearly, like if it is midday (happens in a night, day, or a rainy server).
- Legacy ID
This is a common issue in many games with day/night and dynamic weather. I know that Rust for instance does this same thing and actually when first getting into an ARMA II game occasionally it takes a second for the world to show its true colors. I think it is something that happens as the world is initializing and your client is syncing with the server. Not sure if they can actually prevent this. And a second isn't a large amount of time anyway.