Knowing how to store cannabis properly matters everywhere, but on a tropical island it matters twice as much. On Koh Samui, the air is warm all year round, the sun is intense and the humidity is often well above 70%. Those are perfect conditions for a holiday and terrible ones for a flower left in the wrong place. Within days, a beautiful, aromatic flower can dry out, lose its aroma or, worse, start to grow mould.
This guide explains, step by step, how to store cannabis in a hot and humid climate: what damages flowers, the ideal humidity and temperature, which containers to use, how humidity packs work, what to do in a hotel room or villa, how to recognise mould and how long flowers keep. It also covers the legal side, because in Thailand how you keep your cannabis matters as much as where it came from.
Key takeaways
- Light, heat, air and the wrong humidity are the four enemies of stored cannabis.
- Aim for a relative humidity between 55% and 62%, in a cool, dark place.
- Use an airtight glass jar, ideally with a two-way humidity pack, rather than plastic bags.
- Never leave cannabis in a scooter seat, a car or on a sunny balcony.
- Discard any flower that shows signs of mould, and keep prescribed products in their labelled packaging.
In this article
Why storage matters more in the tropics
Cannabis flowers are delicate. Their value lies in the trichomes, the tiny resin glands that contain the cannabinoids and the aromatic terpenes. Those compounds are sensitive to their environment, and the tropics push every factor in the wrong direction.
Heat speeds up chemical reactions, so cannabinoids degrade faster and terpenes evaporate more quickly. Strong light breaks down THC, turning it gradually into CBN, a milder cannabinoid. High humidity encourages mould, while air-conditioned rooms can swing the other way and dry flowers until they crumble.
The good news is that good storage is simple and inexpensive. With a proper jar, a stable place and a little attention, you can keep flowers in excellent condition throughout your stay.
The four enemies of stored cannabis
To understand how to store cannabis well, it helps to know exactly what you are protecting it from.
Light
Light, and especially ultraviolet light, is one of the most damaging factors for stored cannabis. Research on cannabis storage has long shown that flowers kept in the light lose THC much faster than those kept in the dark. Direct sunlight through a window is the worst case.
Heat
Warmth makes terpenes evaporate and accelerates the degradation of cannabinoids. It can also dry flowers out and, combined with humidity, encourage mould. The warmer the storage place, the shorter the life of the flower.
Air
Oxygen slowly oxidises cannabinoids and terpenes. A jar that is opened constantly, or a bag that is not airtight, exposes the flowers to a steady flow of fresh air. Too much air in a container that is only half full has the same effect over time.
Humidity
Humidity is the trickiest enemy because it works in both directions. Too much, and mould can grow. Too little, and the flowers become brittle, the trichomes break off and the aroma fades. The goal is stability within a narrow range.
The ideal storage conditions
Here are the conditions most producers and dispensaries aim for.
| Factor | Target | Why it matters |
|---|---|---|
| Relative humidity | 55% to 62% | Prevents both mould and over-drying |
| Temperature | Cool and stable, ideally below 25°C | Slows the loss of terpenes and cannabinoids |
| Light | Complete darkness | Protects THC and aroma from degradation |
| Air | A sealed, well-filled container | Limits oxidation |
On Koh Samui, the temperature target is the hardest to reach without air conditioning. The best practical solution is usually a drawer or cupboard inside an air-conditioned room, away from windows and outside walls.
Humidity above about 65% for long periods significantly increases the risk of mould. That is why a jar left open in a humid bungalow is a bad idea, even if it is in the shade.
Choosing the right container
The container is the heart of good storage. Here is what works and what does not.
- Airtight glass jars are the gold standard. Glass does not transfer smells, does not create static and seals well. Tinted or opaque jars add protection from light.
- Size matters. Choose a jar that the flowers fill without being crushed. A large jar with a small amount of cannabis contains more air.
- Original sealed packaging is a good option as long as it stays closed. Once opened, transfer the flowers to a jar if you will keep them for more than a few days.
- Plastic bags are a poor choice. They are rarely airtight, they can create static that pulls trichomes off the flowers, and they offer no protection against crushing.
- Metal tins can work if they seal well, but check that they are clean and do not transfer any smell.
Whatever you use, keep it clearly labelled and out of reach of children.
Humidity packs explained
Two-way humidity packs are small sachets that release or absorb moisture to keep the air inside a container at a set relative humidity, usually 58% or 62%. You simply place one in the jar with the flowers.
In a humid climate, they help stop flowers from getting too wet. In an air-conditioned room, they stop them from drying out. They are one of the simplest ways to keep storage conditions stable, and many dispensaries use them.
A few tips: choose the right size for your jar, replace the pack when it becomes hard and crunchy, and never let it touch wet surfaces. For longer storage, a small digital hygrometer inside the jar lets you check the humidity at a glance.
How to store cannabis in a hotel room or villa
Holiday accommodation brings its own challenges. Air conditioning dries the air, bathrooms are steamy, balconies are hot and housekeeping comes in every day. Here is how to store cannabis sensibly while travelling.
- Pick the right room. An air-conditioned bedroom is better than a humid bathroom or a hot living area.
- Choose a dark, closed place, such as a drawer or a wardrobe, away from windows.
- Keep the jar closed and open it only when needed.
- Use the room safe if there is one, to keep the product secure and away from children.
- Respect the house rules. Many hotels and villas ban smoking indoors, and some ban cannabis entirely.
- Never leave it on a balcony, a windowsill or near the kitchen, where heat and steam are highest.
If you are sharing accommodation with children, store cannabis in a locked place. Children and pets can be seriously harmed by accidentally eating cannabis products.
The fridge and freezer myth
Because heat is the enemy, many people think the fridge is the answer. It is not. A fridge is humid and its temperature and humidity change every time the door opens, which can cause condensation on the jar and encourage mould. Opening a cold jar in warm, humid air can make condensation even worse.
The freezer is not a good idea either for everyday storage. Freezing makes trichomes brittle, so they break off easily when the flowers are handled. Some producers use carefully controlled cold storage for long-term keeping, but that is very different from a hotel minibar or a kitchen freezer.
A cool, dark and stable place is always better than a cold, damp one.
Transport: the scooter seat trap
On Koh Samui, many visitors ride scooters, and it is tempting to keep things in the compartment under the seat. It is one of the worst places for cannabis. Parked in the sun, that compartment can become extremely hot, and a few hours there can ruin the aroma of a flower or dry it out completely. The same goes for a car parked in the sun.
When you move around the island, keep any prescribed product in its labelled packaging, in a bag you carry with you, and bring it back to a cool place as soon as possible. Never drive or ride a scooter after using cannabis.
How to spot mould and what to do
In a humid climate, checking for mould is part of good storage. Look for:
- white or grey fuzz, especially deep inside the flower;
- a fine powdery white coating on the surface;
- dark spots, discoloured patches or webbing;
- a musty, damp or mildew-like smell.
If you notice any of these signs, do not use the flower, and do not try to save it by drying it or cutting off the visible part. Some moulds can be harmful to health, especially for people with a weakened immune system, as the US Centers for Disease Control and Prevention explains. Dispose of it safely and check the rest of the jar.
Prevention is easy: keep the humidity in the right range, never store damp flowers, and never close a jar that contains condensation.
How long does cannabis stay fresh?
Well-stored flowers can keep good quality for several months, but they change slowly over time. THC gradually degrades into CBN, the aroma fades and the texture becomes drier. Studies on long-term storage, such as work published in the Australian Journal of Forensic Sciences, show that light and warmth speed up this loss considerably.
For the best experience, use flowers within a few weeks of opening, keep them sealed between uses and check the packaging date when you buy them. Remember that in Thailand, a prescription covers a maximum of 30 days, so there is little reason to stock more than you need.
Storing different kinds of products
Flowers are not the only products people keep, and each type has its own needs.
- Pre-rolls dry out faster than whole flowers, because the plant material is ground and exposed. Keep them in their tube or a small airtight container, in the same cool, dark place.
- Edibles such as chocolates, cookies or gummies are sensitive to heat: chocolate melts and gummies stick together in the tropics. Follow the storage instructions on the label, keep them in their original child-resistant packaging, and store them where children cannot reach or mistake them for sweets.
- Oils and tinctures, including CBD oils, should be kept tightly closed, upright, in a dark and cool place. Light and heat degrade them over time.
Whatever the product, keep the label. It tells you what the product is, how strong it is and, for prescribed products, shows that it was obtained legally.
Common storage mistakes
These are the mistakes we see most often, and all of them are easy to avoid.
- Leaving the jar open on a table between uses.
- Keeping flowers in the plastic bag they came in for weeks.
- Storing cannabis in the bathroom, where showers create steam.
- Putting a jar straight from an air-conditioned room onto a hot balcony.
- Crushing flowers into a container that is too small.
- Forgetting a humidity pack that has dried out and stopped working.
Storage and the law in Thailand
Storage also has a legal side. In Thailand, cannabis flowers can only be supplied to patients with a valid prescription, as we explain in our guide to the PT33 prescription. Keeping your product in its original, labelled packaging, together with the prescription and receipt, allows you to show that it was obtained legally and in the quantity prescribed.
Never repackage prescribed cannabis into unlabelled bags, and never carry more than your prescription allows. When your stay ends, do not pack cannabis in your luggage: taking it out of Thailand is a serious offence. Our guide on whether weed is legal in Thailand explains the rules in detail.
Ten simple rules for storing cannabis in the tropics
To sum up, here are the ten rules we give visitors who ask us how to store cannabis on Koh Samui.
- Keep it in an airtight glass jar or its sealed original packaging.
- Store it in the dark, away from windows.
- Keep it cool, ideally in an air-conditioned room.
- Aim for a relative humidity of 55% to 62%.
- Use a two-way humidity pack for anything you keep more than a few days.
- Choose a jar the right size for the amount you have.
- Avoid the fridge, the freezer, the bathroom and the balcony.
- Never leave it in a scooter seat or a parked car.
- Check regularly for mould and discard anything suspicious.
- Keep it labelled, secure and out of reach of children.
Storage and quality go together
Good storage does not improve a flower, but it preserves the quality it had when it left the dispensary. A carefully grown, well-cured flower deserves the same care afterwards. Our guide to cannabis quality explains what to look for when you choose a flower, and our article on cannabis terpenes explains why aroma is the first thing to disappear when storage goes wrong.
If you have questions about storage during your stay on Koh Samui, you are welcome to contact our team.
Frequently asked questions
What is the best way to store cannabis in a hot climate?
In an airtight glass jar, in a dark drawer or cupboard inside an air-conditioned room, ideally with a two-way humidity pack set to 58% or 62%.
Should I keep cannabis in the fridge?
No. The fridge is humid and its conditions change each time the door opens, which can cause condensation and mould. A cool, dark and stable place is better.
How do I know if my cannabis has gone mouldy?
Look for white or grey fuzz, a powdery coating, dark spots or webbing, and trust your nose: a musty smell is a warning sign. Do not use any flower that might be mouldy.
Can I store cannabis in a plastic bag?
It is not recommended. Plastic bags are rarely airtight, they can pull trichomes off through static, and they offer no protection from crushing.
Is the hotel safe a good place to store cannabis?
It can be, as long as the safe is inside an air-conditioned room and not in direct sunlight. It keeps the product secure and out of reach of children. Keep the jar closed and the product in its labelled packaging.
How long does cannabis stay fresh?
Well-stored flowers keep good quality for several months, but they slowly lose aroma and potency. For the best experience, use them within a few weeks of opening.
Sources
- Aspergillosis, US Centers for Disease Control and Prevention.
- Lindholst C., Long term stability of cannabis resin and cannabis extracts, Australian Journal of Forensic Sciences, 2010.
Last updated: September 2026. This article is general information, not medical or legal advice. In Thailand, cannabis flowers may only be supplied with a valid prescription.
