Hello help first grow ak47 easy ryder

my grow room temps has a lot of up and down temps it goes from 89 degrees to 83 and sometimes 77 with the humidty going from 25% to 55% is that ok or is that stress to the plant but the plants are looking healthy...help by the its three plant under a 400watt mh bulb

try to keep it at 77 and 89 is def pretty high. its ok, but 85f is about as high as it should fluctuate, and definitely not for very long.

it hit 95 like twice and caught it quick but if it hit 90 i heard that it slows the growth how long after i get bac to normal temps does it grow at a normal rate