How dry does the deck need to be after cleaning it to apply the stain?

How dry does the deck need to be after cleaning it to apply the stain?
Deck 14 months old (live in SE Tennessee)?

I have a covered porch 26 yrs old (good shape with some more wear on western side)?

Also a set of uncovered stairs (slight overhang from roof but lots of blown in rain / and occasional snow & ice. Itis the also 26 yrs old but the most worn for the weather.

All treated pine (first set with the arsenic (1988 from my understanding) and the deck with the copper (14 months old).

Thanks for your help!

Sincerely,

Waldensian!