If you are planning on welding nuclear reactors then yes everything needs to be perfect, but for the home shop, just don't worry about it, i've welded with soaking wet electrodes onboard boat in a storm, without any porosity and it still holds, just keep them in a box on a shelf and don't worry about them.
This is true for 6010/6011, a little moisture does not affect them seriously. 7018 is a different matter.
"Storing Low Hydrogen Stick Electrodes
Low hydrogen stick electrodes must be dry to perform properly. Unopened Lincoln hermetically sealed containers provide excellent protection in good storage conditions. Opened cans should be stored in a cabinet at 250 to 300°F (120 to 150°C)
Low hydrogen stick electrode coatings that have picked up moisture may result in hydrogen induced cracking, particularly in steels with a yield strength of 80,000 psi (550 MPa) and higher.
Moisture resistant electrodes with an "R" suffix in their AWS classification have a high resistance to moisture pickup coating and, if properly stored, will be less susceptible to this problem, regardless of the yield strength of the steel being welded. Specific code requirements may indicate exposure limits different from these guidelines.
All low hydrogen stick electrodes should be stored properly, even those with an "R" suffix. Standard EXX18 electrodes should be supplied to welders twice per shift. Moisture resistant types may be exposed for up to 9 hours.
When containers are punctured or opened, low hydrogen electrodes may pick up moisture. Depending upon the amount of moisture, it will damage weld quality in the following ways:
1. A greater amount of moisture in low hydrogen electrodes may cause porosity. Detection of this condition requires x-ray inspection or destructive testing. If the base metal or weld metal exceeds 80,000 psi (550 MPa) yield strength, this moisture may contribute to under-bead or weld cracking.
2. A relatively high amount of moisture in low hydrogen electrodes causes visible external porosity in addition to internal porosity. It also may cause excessive slag fluidity, a rough weld surface, difficult slag removal, and cracking.
3. Severe moisture pickup can cause weld cracks in addition to under-bead cracking, severe porosity, poor appearance and slag problems.
Storing and Redrying Non-Low Hydrogen Electrodes
Electrodes in unopened Lincoln cans or cartons retain the proper moisture content indefinitely when stored in good condition.
If exposed to humid air for long periods of time, stick electrodes from opened containers may pick up enough moisture to affect operating characteristics or weld quality. If moisture appears to be a problem, store electrodes from the opened containers in heated cabinets at 100 to 120°F (40 to 50°C). DO NOT use higher temperatures, particularly for electrodes from the "Fast Freeze" group.
Some electrodes from wet containers or long exposure to high humidity can be re-dried."
https://www.lincolnelectric.com/en-us/support/welding-how-to/pages/storing-electrodes-detail.aspx
I was given a bundle of assorted rods when I bought my Lincoln AC225. Don't know how long they had been stored in the open. The 309 stainless rods were fine. The flux was falling off the 7018. Humidity in California is generally quite low.