I have 2 autoflowers in a tent under a HID set up. They are about 3 weeks into flowering and currently are on a 20/4 schedule getting about 50 DLI. Temps normally run about 82, with the light contributing the vast majority of the Heat.
With autos, can I just shut off the light for the hottest part of the day? Will it affect anything or weird them out?
I can’t say this is any scientifically verified evidence, if that’s what you’re looking for, but this time of year I make my dark periods for flowering areas during the afternoon. It gets a little warmer than I’d like in there otherwise & I don’t want to get into dedicated HVAC for just that small area. I’m not seeing anything to worry about here. Seems ok to me. Those are photos though.
Oddly enough, I have a couple of those double grape x kraken autos in a greenhouse right now w/ no AC… just an exhaust fan. They’re males and I was curious to see how they’d fare. It would be cool to use the greenhouse to gather auto pollen during the long days, then photo pollen over the winter. Anyhow, to my surprise, with temps in the greenhouse of 100-105 during the day, those males look like they couldn’t possibly care less about the heat. They’re looking great.
Man, I just re-read that and noticed I didn’t answer your question and just said a bunch of shit… I must be getting old and doing that thing where you just open your mouth and start spraying words at people… sorry bud.
You are all good here, my friend. Made sense to me, and I appreciate your help. Both of my DGs (one outside, too) are thriving and not bothered by the heat yet, but we’re looking at 100+ in the next few days. . .
I hear you about lights on at night, but I don’t want to mess with their schedules too much right now. Just kill the tent light and let them enjoy some dimmer, ambient light for a while, and some cooler temps.
Autos are not affected by light schedules, they will do “their thing” independently of the light hours exposure … 
ding ding – i think this is all i needed. Thanks, George. 
Just remember to adjust ppm / ec as plants drink a lot more to cool down in heatwave , and we don’t want to go overboard with daily food intake kind off
: )
good call, thank you!