The Right Temperature & Humidity for Storing Cannabis Post-Harvest

Storing cannabis properly after harvest is crucial to preserving potency, flavor, and shelf life. Temperature and humidity control play the biggest roles in preventing mold, terpene loss, and cannabinoid degradation.

In this guide, we’ll break down the ideal temperature and humidity ranges, how they impact cannabis storage, and the best ways to keep your flower fresh for months.

1. Why Temperature & Humidity Matter in Cannabis Storage

After cannabis is harvested and cured, how you store it determines its long-term quality. Poor storage conditions can lead to:

❌ Mold growth – Excess moisture encourages mold, making buds unsafe to consume.
❌ THC degradation – High temperatures break down cannabinoids, reducing potency.
❌ Terpene loss – Improper storage leads to flavor and aroma evaporation.
❌ Over-drying or rehydration – Fluctuations cause brittle, harsh flower or too-dense, sticky buds.

💡 Goal: Maintain stable conditions that lock in terpenes, cannabinoids, and moisture content.

2. Best Temperature for Storing Cannabis Post-Harvest

🔹 Ideal Temperature Range: 55-65°F (13-18°C)
🔹 Absolute Maximum: 70°F (21°C) – Anything higher accelerates THC breakdown

Why Temperature Matters:

✅ Keeps Trichomes Intact – Higher temperatures cause trichomes to become brittle or sticky.
✅ Slows THC Degradation – Heat converts THC into CBN, reducing potency.
✅ Prevents Terpene Evaporation – Terpenes degrade quickly at high temperatures, killing flavor & aroma.
✅ Avoids Mold & Mildew – Warm environments promote mold growth, especially with excess humidity.

3. Best Humidity for Cannabis Storage

🔹 Ideal Humidity Range: 58-62% RH (Relative Humidity)
🔹 Too Low (<55% RH): Over-drying leads to brittle buds, harsh smoke.
🔹 Too High (>65% RH): Risk of mold and mildew development.

Why Humidity Control Is Critical:

✅ Maintains Bud Moisture – Prevents cannabis from drying out and losing terpenes.
✅ Stops Mold Growth – Keeping RH below 65% eliminates mold risk.
✅ Preserves Cannabinoids – THC and CBD remain stable in controlled humidity.

💡 Pro Tip: Use humidity control packs (58-62% RH) inside storage containers to regulate moisture levels.

4. The Impact of Temperature & Humidity on Cannabis Quality

🚨 Key Takeaway: Stable, cool temperatures and moderate humidity ensure the longest shelf life and best smoking experience.

5. How to Maintain Proper Storage Conditions

✅ Store Cannabis in Airtight Containers

✔ Glass jars (Mason jars) – Best for preserving terpenes & cannabinoids.
✔ Mylar bags – Blocks light, air, and moisture, great for bulk storage.
✔ Vacuum sealing – Removes excess oxygen, ideal for long-term storage.

🚫 Avoid: Plastic bags, clear jars in direct light, or paper bags (cause terpene loss & static cling).

✅ Keep Cannabis Away from Heat & Light

✔ Store in a cool, dark place (closets, cabinets, or cellars).
✔ Use UV-resistant jars or Mylar bags for extra protection.
✔ Keep containers away from appliances that produce heat (ovens, radiators).

🚫 Avoid: Sunlight, warm attics, or near electronics (heat & UV degrade THC).

✅ Use Humidity Control Packs

✔ Add 58-62% RH packs inside jars or Mylar bags.
✔ Prevents buds from drying out or getting too moist.
✔ Available in brands like Boveda or Integra Boost.

🚫 Avoid: Wet paper towels or sponges (can introduce mold).

✅ Monitor Humidity with Hygrometers

✔ Small digital hygrometers help track RH levels inside containers.
✔ If humidity goes above 65%, air out jars for a few hours.
✔ If RH drops below 55%, add a humidity pack.

🚫 Avoid: Storing cannabis in refrigerators (RH fluctuates too much).

6. Long-Term Cannabis Storage: Best Practices

🔹 For 6+ Months Storage:
✔ Use vacuum-sealed Mylar bags for airtight protection.
✔ Keep in a cool, dark place (55-60°F, 58-62% RH).
✔ Store away from strong-smelling items (coffee, spices) to avoid contamination.

🔹 For 1+ Year Storage:
✔ Deep freeze at 32-40°F using vacuum-sealed glass jars.
✔ Prevent moisture exposure with food-safe silica gel packets.
✔ Only thaw at room temp before opening to avoid condensation.

🚨 DO NOT: Store cannabis in a standard freezer – Ice crystals damage trichomes.

7. Common Mistakes to Avoid

🚫 Leaving Cannabis in Plastic Bags – Traps moisture, degrades THC.
🚫 Storing Above 70°F – Speeds up cannabinoid & terpene breakdown.
🚫 Using Paper or Cardboard Boxes – Absorbs moisture, promotes mold growth.
🚫 Placing in the Fridge – Humidity fluctuations cause condensation & mold.
🚫 Forgetting to Check RH Levels – Buds can dry out or rehydrate too much.

8. Final Takeaway: Best Storage Setup for Maximum Freshness

✔ Ideal Cannabis Storage Conditions

✅ Temperature: 55-65°F (13-18°C)
✅ Humidity: 58-62% RH
✅ Containers: Glass jars, Mylar bags, vacuum-sealed packaging
✅ Storage Location: Cool, dark, away from heat & light
✅ Extra Protection: Humidity packs & hygrometers

By following these guidelines, you’ll preserve potency, flavor, and freshness—keeping your cannabis top-shelf for months or even years.

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