I believe anywhere in the high 70s to mid-80s is perfect for marijuana plants I run my room about 45 to 55% humidity when you're in cloning stage though you want that humidity to be about 100% the warmer the better they will root out in 9 to 10 days if not sooner I've seen Roots after 7 Days doesn't mean it's ready to be planted but I've seen roots especially when it's warm and humid for clones. Now when you're growing your plants and you have temperature that warm you're going to want to have good airflow you're going to want to see your plants kind of waving in the wind so to speak like you would see trees out in nature.