White spots on auto

Can anyone tell me what the white spots are on my autoflower?

What are your watering habits? Could be overwatering. How about RH? Another possibility is powdery mildew. Any air movement?

They’re outside so could be overwatering. We’ve had a lot of rain lately. I only water them when they’re dry and the ph is good

There are three plants. Two autos and one photo and this is the only one with the spots

My bad rh it’s through the roof lately.