Cannabis Dry and Cure Humidity Chart: Target RH by Stage

A cannabis dry and cure humidity chart pairs each stage after harvest with a target relative humidity: about 55 to 65% RH while drying, 58 to 62% RH while curing, and 55 to 62% RH in storage. The one number most growers memorize is 60% RH at roughly 60°F, a balance point that lets flower release moisture slowly instead of sealing wet stems inside brittle buds.

Cannabis dry and cure humidity chart at a glance

Relative humidity describes how much water vapor the air holds at a given temperature. In a drying room or a curing jar, that reading tells you whether water is leaving the plant too fast or barely leaving at all.

ideal humidity for drying marijuana buds

Dry, days 1 to 3: 60 to 65% RH at 65 to 70°F. Whole plants or branches hang and shed surface moisture.
Dry, days 4 to 7: 58 to 62% RH. Stems flex instead of snapping, and buds feel dry outside but soft inside.
Dry, days 8 to 14: 55 to 60% RH. Small stems snap when bent. This is the window to trim and jar.
Cure, weeks 1 to 2: 58 to 62% RH. Burp jars or bags once a day.
Cure, weeks 3 to 8: 58 to 62% RH. Burp every few days, then weekly.
Long-term storage: 55 to 62% RH, dark, near 60°F.

Treat the day counts as guidance rather than law. Room temperature, bud density, and the amount of plant material in the space all shift the timeline.

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Why relative humidity matters more than a calendar

Curing is a slow chemical process. Chlorophyll and starches break down while moisture inside the flower redistributes from the center of the bud to the surface. If the room or jar sits below about 55% RH, that process stalls and the flower stays harsh and hay-like. If it climbs above about 65% RH, the risk of mold and mildew rises sharply, and you may not notice it until the bud is already spoiled.

Temperature works alongside humidity. Warm air holds more moisture and pulls it out of the plant faster, which is why a 60°F room dries more evenly than a 78°F closet. Cooler is easier to control, but below about 60°F the process slows enough that bud can sit wet for too long.

Water activity versus relative humidity

RH is a property of the air around the flower. Water activity, written as Aw, measures how much moisture is available inside the plant material itself. Commercial growers often target 0.55 to 0.65 Aw alongside a 58 to 62% RH environment. The two track each other closely, so a humidity reading plus a decent hygrometer covers most home grows.

The dry stage in practice

Hang in a dark room with gentle air movement, not a fan blowing directly on the plants.
Check RH twice a day and keep it in the 55 to 65% band.
Start testing stems around day 7. Bend, do not pull.
Move to jars or bags when small stems snap and buds feel dry but spongy.

The cure stage in practice

Fill containers about three-quarters full so air can circulate.
Hold 58 to 62% RH. Two-way humidity packs can help you stay in that range.
Burp daily for the first two weeks, then taper off.
If the jar reads above 65% RH, leave it open longer and rotate the flower.

Common humidity mistakes

Drying too fast. Below 55% RH, terpenes evaporate and the smoke turns sharp.
Jarring too wet. Buds that feel damp at the stem push jars over 65% RH within hours.
Trusting one hygrometer. Inexpensive meters drift. Compare two before you rely on a reading.
Ignoring light and heat. Storage humidity can be perfect while a sunny shelf still degrades the flower.

Quick answers

What humidity should I cure cannabis at?

Most growers cure at 58 to 62% RH. That range is low enough to prevent mold and high enough to keep the cure active.

Can I cure at 65% RH?

It is risky. At or above 65% RH, mold becomes a real concern, especially in sealed containers with dense buds.

Do I need a humidity pack?

No, but a two-way pack smooths out swings in small jars and keeps long-term storage steady. Add one after the first week of curing, not on day one.