Agree and great advice from @MidwestGuy. I too am one of those growers that don’t chase VPD numbers, I just keep the environmental conditions in range per the growth stage 
I’m reviving this comment…I just flipped a plant to flower, and in need of some info.
would you still target 50% early flower if your temps are hovering around the 80-85 range?
In the midst of a crazy heat wave in SoCal. (temps otherwise hover 78-81) I’ve got great airflow; fan above canopy, fan on floor bouncing into side tent for circulation under canopy, exhaust wide open, and little fans built into lights turned up.
I can boost my RH with the humidifier in tent. Not really chasing VPD, but according to the charts, with the higher temps, boost RH…should I consider that or keep RH 45-50% ish and roll with that the rest of the way?
thanks!
I just realized I replied specifically. If anyone else sees the post above and has insight, I would appreciate it!
I would say with temps reaching 85 maybe target 55-60% rh so the plant doesn’t transpire to much and potentially stress it. Ideally lower rh is better but during the heat wave having the extra rh can help prevent heat stress and again transpire to rapidly causing stress. If you have enough air flow and canopy is maintained so you don’t have micro climates you should be fine.
If you are outside nominal VPD I’d rather it were on the high side myself.
Thanks for the follow ups!
Looking good to me my friend