Cannabis Storage Conditions: Temperature and Humidity
Store cannabis at 59-70°F and 55-65% relative humidity in an airtight, light-blocking container. Here is how temperature and humidity protect potency.
Start With the Number, Then Fix the Rest
If you only remember one thing, remember this: 58 to 62 percent relative humidity (RH) is the range that keeps cured flower intact. I aim for 62 percent when a jar goes into long-term storage and 58 percent for something I plan to grind within a week or two. Below 55 percent, trichomes turn brittle and the flower crumbles to dust in your fingers. Above 65 percent, you are running a mold experiment you did not sign up for.
cannabis storage humidity 62 percent
Everything else in a storage setup (the jar, the hygrometer, the pack, the temperature) exists to hold that number steady. Buy for the number, not for the packaging.
Humidity for Long Term Cannabis Storage: 58% to 62% RH
What to Look For When You Buy
1. A two-way humidity pack
Two-way packs add moisture when the jar runs dry and absorb it when the jar runs wet. That is the whole point. One-way tricks, like a slice of bread, a piece of orange peel, or a damp paper towel, push humidity up and never pull it back down. They also transfer flavor and invite mold. Look for packs rated at 58 percent or 62 percent, sized to your container volume, and swap them out when they turn stiff or crunchy.
optimal moisture level for storing marijuana
2. A calibrated hygrometer
Small digital hygrometers cost less than a gram and take the guesswork out. Buy one per jar if you keep several strains. Salt-test it before you trust it: seal it in a bag with a bottle cap of damp salt for 6 to 8 hours. It should read near 75 percent. If it does not, return it.
cannabis storage conditions temperature humidity
3. An airtight container that blocks light
Amber glass with a rubber gasket and a clamp lid is the standard. Mason jars work fine. Opaque beats clear because light degrades THC over months. Skip plastic bags for anything longer than a week, and skip any container that still smells like last night's dinner.
Parameters That Matter
- Relative humidity: 58 to 62 percent. Use 62 for months, 58 for weeks.
- Temperature: 60 to 70 F. Cool, stable, dark. A closet beats a warm shelf.
- Headspace: fill the jar about 75 percent. Too much air makes the pack work harder.
- Light: none, or as close to none as you can manage.
- Pack ratio: one 8 gram pack per ounce is a common starting point. Bigger containers need more.
Pitfalls I See People Hit
- Chasing 70 percent. It feels sticky and fresh for a day, then it gets fuzzy.
- The refrigerator. Fridges are dry and cycle temperature constantly. Jars come out, condensation forms, flower gets wet.
- The freezer. Fine for some extracts, rough on flower. Every frost cycle knocks trichomes loose.
- Burping a cured jar daily. Burping belongs in the first week or two of curing, not in storage. Every open resets humidity.
- Trusting the pack alone. A pack in a leaking jar does nothing. Seal first, then regulate.
- Mixing strains. Terpenes migrate. One loud strain can make a mild one taste like it.
The Short Version
Buy 62 percent two-way packs for flower you plan to keep for months, 58 percent packs for anything you smoke within a couple weeks, a digital hygrometer, and an airtight amber jar. Keep it dark and between 60 and 70 F. Check the reading once a week for the first month, then leave it alone. That is the entire system, and it outperforms every forum trick out there.