Thailand Travel Guide: What to Pack and When to Go | 20 Years of Hard-Won Lessons

After 20 years of traveling to Thailand, I’ve learned what to bring, what to leave behind, and when to go. This guide cuts through the noise and tells you what actually matters.

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Thailand Has Three Seasons

Cool Season (November - February)
└ Best season for travel
└ Less rain, comfortable temperatures
└ Clearest sea conditions
└ Higher prices for flights and hotels

Hot Season (March - May)
└ Hottest time of year, up to 40°C
└ Songkran water festival
└ Brutal for daytime sightseeing

Rainy Season (June - October)
└ Daily heavy downpours, usually 1-2 hours
└ Cheapest time to travel
└ Lush scenery and great fruit
└ Roads can flood

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The Biggest Trap: Different Regions Have Different Rain Seasons

Thailand is long and narrow, so the weather varies dramatically by region. This catches many travelers off guard.

Bangkok (Central)
└ Hot year-round
└ Rainy season brings evening downpours

Chiang Mai (North)
└ Cool season mornings can drop to 15°C
└ February-April: smoke and PM2.5
　from agricultural burning

Phuket (Andaman Sea side)
└ Rainy season: May - October
└ Many beaches closed to swimming

Koh Tao, Koh Phangan, Koh Samui
(Gulf of Thailand side)
└ Rainy season: October - December
└ Sunny in July and August
└ Better choice than Phuket
　during summer holidays

This is crucial. Travelers who visit Phuket during summer often hit the rainy season. The Gulf of Thailand islands are the smarter choice in July and August.

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The Four Things You Actually Need

After all these years, it comes down to four essentials.

└ Passport (minimum 6 months validity remaining)
└ Cash (Thai baht)
└ Credit card with cash advance function
└ Smartphone

Most other things can be bought locally. Thailand has pharmacies everywhere. Travel light and buy what you need when you need it.

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Do This Before You Leave

TDAC (Digital Arrival Card)
└ Register online up to 72 hours before arrival
└ Free and mandatory

Check your passport validity
└ Must have 6+ months remaining

Sort out your mobile data
└ Check if your current plan covers Thailand
└ If not, get an eSIM before departure
└ SIMs are also available at Thai airports

Install Grab
└ Register your credit card in advance
└ Makes getting around dramatically easier

Travel insurance
└ Check if your credit card includes coverage
└ If not, take out a policy before departure

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For Beach Trips

└ Swimwear
└ Beach sandals
└ Reef-safe sunscreen
└ Motion sickness medication
　(essential for speedboats to islands)
└ Waterproof phone case

Motion sickness medicine is not optional on island ferry routes. The boats can get rough. Bring it regardless of whether you think you need it.

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Things People Forget

Something warm to wear

Long-distance buses and trains in Thailand run their air conditioning at arctic levels. Bring a light jacket or cardigan regardless of the season outside.

Temple-appropriate clothing

Temples turn away visitors in sleeveless tops, short shorts, miniskirts, or ripped jeans. Pack a light cover-up and long pants.

Wet wipes

Street food stalls and public toilets often have no paper. Wet wipes earn their weight every single day.

Reusable bag

Plastic bags are no longer provided free at convenience stores and supermarkets.

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Watch Out on the Plane

Neck pillow
└ Useful for long flights

Inflatable foot rest
└ Some airlines including Thai Airways
　do not permit these
└ Check the rules before packing one

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Never Bring These

E-cigarettes (vapes)
└ Illegal in Thailand
└ Confiscation and heavy fines
└ Leave them at home, no exceptions

Shisha pipes
└ Also prohibited

Regular cigarettes
└ These are fine

E-cigarettes are illegal in Thailand. This surprises many travelers who use them at home. Do not bring them under any circumstances.

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Money and Exchange

Exchange money in Thailand, not before
└ Rates at home airports are poor
└ Bangkok exchange booths offer
　far better rates
└ Look for Super Rich (green or orange signs)

Always carry cash for
└ Street food stalls
└ Tuk-tuks
└ Small local shops
└ Tips
└ Keep small bills handy (20 and 100 baht)

Credit cards work at
└ Mid to large hotels and restaurants
└ Shopping malls
└ Grab ride payments

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Don’t Worry About Food

If the local food isn’t working for you, McDonald’s, Burger King and other fast food chains are everywhere. There’s always a fallback option.

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When Exhaustion Hits

Thailand is hot year-round and sightseeing drains energy fast. Every convenience store stocks energy drinks including the original Thai Red Bull. It works. Keep one handy on long travel days.

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Suitcase or Backpack?

Suitcase makes sense for
└ Bangkok and Chiang Mai city trips
└ Hotel-based travel
└ Buying lots of souvenirs

Backpack makes sense for
└ Island hopping
└ Koh Tao and Koh Phangan involve
　boats, beaches and sandy paths
└ A suitcase becomes a burden fast

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Leave These at Home

Too many clothes
└ Laundry services are cheap and everywhere
└ Buying a local t-shirt is part of the fun

Heavy guidebooks
└ Your phone handles everything

Heeled shoes
└ Bangkok pavements are uneven
└ Sneakers and sandals are all you need

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Final Thoughts

The most important decisions in Thailand are timing and region. Get those right and everything else falls into place.

For everything else, the four essentials cover you. Travel light, buy what you need locally, and enjoy the fact that Thailand makes everything easy.

Just leave the e-cigarettes at home. Every time.