ive never heard of having the temps being hotter during lights off than they are doing lights on doing anything negative.. that is the way i like to run my lihgts, on at night when temps are cooler and off during the mid day heat, and have never had one issue doing so..
i had the same problem a month or so ago when our power went out for a few hours, so i just left the lights off till it was time for them to come back on again, at which time i just turned them on again at their normal time..