There are actually quite a few clouds on Tatooine throughout all three prequels:
https://youtu.be/e3NRzGrt5z0?t=11
https://www.youtube.com/watch?v=yiLVNGl8rew
https://youtu.be/6C--Zttls8I?t=128
Those devices seen around the Lars homestead are moisture 'vaporators, presumably used to pull moisture from the atmosphere, so there’s clearly something up there.
So to answer the original question, I think the presence of clouds on Tatooine in the original film is perfectly fine, even if the ones in the first scene are unusually fluffy.