Depends on the relative humidity in your house and the type of filament you use. I have usually ~30% humidity in my flat.
- PLA reall doesn’t care about humidity. I’ve got some 5yo rolls that still print like new, without storing them air-tight.
- PETG is fussier. After a few days they start to act up. I always have them in the filament dryer while printing.
- Specialist filaments (e.g. Nylon, Carbon, Wood) might be much more hydroscopic, depending on the material.
That’s a bit high. PLA still won’t care, but PETG will probably only print perfectly for a quite short time (maybe a day or two).
That said, depending on what exact blend it is, Silk PLA or other PLAs with additives might also have an issue with humidity.