This is my first Dying Light and I'm already sold that I'm planning to try the other ones but probably after I finish this one as I'm already into it.

About volatiles outside in the daylight,

After going outside, I noticed a few Volatiles lurking around over toward the nearby bridge. The sun had not even set yet, which left me feeling pretty confused about their presence.

I also got confused about it and I even wrote about it in this post.

I understood later after checking the time, that it was 10 PM, not daylight. I was actually inside a power plant that I activated a moment ago. I realized the bright lights washed over the surrounding area as if the sun was still up, which explained why the Volatiles were actively crawling around.