Last few days before the harvest. I'm seeing the beginnings of some more flower buds, but since they're all getting cut down in a few days anyway I'm not worried about it.
The temperature outside has dropped quite a bit, down into single digits. The heat in my apartment has been running more often, and drying out the air. I'm down to 40% RH at 70° with the light on.
I discovered "vapour pressure deficit" recently, and it's fascinating. It has to do with the best balance between temperature and relative humidity, as far as growth is concerned. At 40% RH and 70°, I'm outside the recommended range for fast growth (too dry for that temperature), but within the range used to purposefully stress plants to get certain responses (for example, increased essential oil production in basil). So it may actually be a good thing as this grow finishes.
For the rest of the winter, though, I am going to have to add moisture back into the air. I have a fairly powerful humidifier on the way to humidify the whole room this grow area is in, so that I can keep the good air exchange but also keep the humidity up.