I have an indoor cat, a female shorthair tabby, she's about 18 months
old.  For climate comparisons, I live in Massachusetts, way inland.

She's shedding.  A lot.  At times, I've got cat hair floating on the
breeze of my air cleaner(s), and the top of the back of my recliner is
now tabby colored instead of its original blue.

So... how much shedding is normal, and how much is too much?  She seems
healthy otherwise.  She's not lethargic, though her attention span
isn't very long when I dangle her cat toys in front of her (she'll
pounce and then walk away as opposed to stalk-pounce-shred, repeat).