And it was an article i read which said plants can withstand temps of upto 120 providing the humidity levels dont get high along with them
Well, yes, they CAN withstand those temps. Marijuana is a hardy plant and will live through most anything. The idea is to have
optimum conditions for your plants in order to have them produce optimally. I guarantee you that having temps that high will absolutely cause problems, and your yield and quality will most definitely suffer. Sure, they will live and produce, but not like they could have.
75-85 is a good range for weed. Anything higher than that, and you will start having issues. Not saying you can't produce some fire bud with 100 degree temps, just saying it would have been better at 85. The difference between optimum and just getting by is huge. I can easily pull 5x as much, at a much higher quality, as some of my buddies using the same lights and strains. It's that extra finesse that matters. As you become more experienced, you will be able to tell what these optimum conditions are more easily, as you should be seeing the results first hand.
Just do more research and look at grow journals if you need more convincing. You won't see awesome yields with exorbitant temps. PM me if you want some pointers or a little more advice. I've been around the block so to say.