Yellow Leaves

I have a rooftop outdoor grow in the northeast - mix of Indica and Sativa. The lower leaves are starting to yellow. They are 4 weeks into flowering and I started with Big Bud about 2 weeks into flowering. Is that normal - rest of the plants and buds look good.

We had a rainy september and a few cold night but last few days were like 80 degrees. I was wondering if it may be something else - any ideas?

If I had to guess without pics, I would say its root bound.

absolutely normal for plants to loose leaves in the flowering stage, as long as its not to severe.

if it looses more than half the leaves you can add some N to your fert

does it matter if the plant receives like 22-24 hours of light everyday?View attachment 1830185