Is it OK if DAY AIR TEMPERATURE is about 80°F(26�...

No it's too much difference, the plants won't like it at all! Do you run your lights overnight when it's obviously the coldest?

The best for the plants is a different of maximum 10*. The plant will survive it, but I guess the grow will go a lot slower if there is a difference of more than 10 degrees. Good luck with the rest of the grow

It's not ok at all , it's a 16°C difference between night and day so it can makes your plant turns hermies but it's not the only problem because she have that temperature shock everyday AND the lower temps is too low , at 10°C the plant is not growing she's just trying not to die. If you want to harvest these plants you should consider buying a small heater

hey there Ashlee, so uhmmmmm no basically it's not good but the plants will live, for the cold temp and the big variation it will stunt the plant, and if the condition persists probably it will stunt the plant forever... but actually the cannabis plant will probably survive, so it's not only bad news. Hope this helps ! 🚀