(Please Help!!) Yellow leaves

My blue dream has been getting lots of yellow leaves.. looks dry and unhealthy
I just flipped to flower, and it’s currently getting 12hrs of light per day. It’s extremely hot in Cali with inside tent temperature raging between (80-85degree.)

Looks like they’re thirsty. Also, they appear to have a nitrogen deficiency. Next time you water, feed your veg nutrients. Don’t over do it though. Give about half the normal amount and see how they respond.

You need to provide some basic info.
A guess would be an N deficiency as that causes the older lower leaves to turn yellow and pale over time.

1 What are you growing in?
2 What nutrients are you using and at what PPM?
3 What is the PH of your nutrient solution?
4 How often are you watering?
5 Did you add any CalMag etc to your solution before adding nutrients?
6 What water are you using...tap or RO?
7 What is the light intensity, DLI / PPFD or Lux if you know?

80 - 90 is pretty hot, but not scorching or the end of the world.