The "perfect" drying conditions for cannabis are those that slow moisture loss evenly, protect terpenes, and prevent mold. In commercial and professional cultivation, this is treated as an environmental control process, not a simple time-based step.

 

Ideal Cannabis Drying Conditions (Industry Standard)

1. Temperature

Target: 60–65°F (15–18°C)
Acceptable range: 55–68°F (13–20°C)

Lower temperatures preserve terpenes and cannabinoids

Temperatures above 70°F accelerate drying and cause:

Harsh smoke

Terpene loss

Chlorophyll lock-in

 

2. Relative Humidity (RH)

Target: 55–60% RH
Critical rule: Never exceed 62% RH

RH below 50% = overdrying, brittle buds

RH above 60% = high mold risk

55–60% RH allows slow, uniform moisture migration from stem to flower

 

3. Airflow

Goal: Gentle, indirect air exchange

Air should circulate the room, not blow directly on buds

Recommended:

Oscillating fans aimed at walls or ceilings

4–6 air changes per hour (ACH)

Direct airflow causes:

Uneven drying

Exterior overdrying while cores remain wet

 

4. Darkness

Requirement: Complete darkness

Light degrades THC and terpenes

Dry rooms should be sealed from:

Sunlight

Grow lights

UV exposure

 

5. Drying Duration

Optimal drying time: 7–14 days

Small plants or low humidity: 7–9 days

Large colas or dense buds: 10–14 days

Drying is complete when:

Small stems snap instead of bending

Bud exterior is dry but not crumbly

Rushing the dry phase is the most common quality failure in cannabis production.

 

Recommended Environmental Setpoints

Parameter	Ideal Setting
Temperature	60–65°F (15–18°C)
Relative Humidity	55–60%
Light	Total darkness
Airflow	Indirect, gentle
Duration	7–14 days

 

Equipment Considerations

Dehumidifier

Use a commercial or grow room dehumidifier

Cannabis dehumidifiers can avoid short cycling; continuous low-load operation is preferred

Target dew point stability, not just RH

HVAC

Cooling is often needed even during drying

Maintain temperature independently of humidity

Monitoring

Use calibrated hygrometers at canopy height

Monitor VPD or dew point for consistency

Data logging is strongly recommended for compliance and repeatability

 

Common Drying Mistakes

Drying at 40–45% RH “to avoid mold.”

Using space heaters or high heat

Pointing fans directly at buds

Drying in rooms without humidity control

Inconsistent day/night conditions

 

Professional Insight

High-quality cannabis is grown in the veg and flower stages, but it is made or ruined during drying. A slow, controlled dry preserves terpene expression, smoothness, and bag appeal far more than genetics alone.