The mistake in almost every packing list is treating Costa Rica as one climate. It isn't. A typical two-week trip crosses four genuinely different ones, and what's right for Arenal is wrong for Guanacaste.
Start here: which Costa Ricas are you visiting?
Before the list, look at your itinerary and tick the regions. Almost everything else follows from this.
Region
Typical destinations
What it's like
Rainforest / volcano
La Fortuna, Arenal, Sarapiquí
Warm, humid, rain possible any month
Cloud forest
Monteverde, Santa Elena
Cool, windy, wet. Altitude changes everything
Dry Pacific
Tamarindo, Papagayo, Conchal, Flamingo
Hot and dry, strong sun, hottest region
Humid Pacific & Caribbean
Manuel Antonio, Uvita, Puerto Viejo
Hot, very humid, rain in short bursts
The single biggest packing mistake we see: people pack for the beach and then go to Monteverde. Cloud forest sits high in the mountains and is often genuinely cold, windy and wet — visitors in shorts and a tank top are miserable there. One fleece fixes it.
The core list — everywhere, every month
Light packable rain jacket — not a heavy shell. Rain is warm and brief; a thick jacket just makes you sweat
Reef-safe sunscreen — the sun here is close to the equator and stronger than most visitors expect, including on cloudy days
Insect repellent — most needed at dawn and dusk, in the lowlands and on the Caribbean side
Closed shoes you don't mind ruining — trails are muddy, and many hanging-bridge and waterfall sites require closed footwear
Quick-dry clothing — cotton stays wet for a very long time in this humidity
Dry bag or waterproof phone pouch — for boat trips, rafting, waterfalls and sudden downpours
Reusable water bottle — tap water is drinkable in most of the country, including San José and the main tourist towns
Small daypack — for the day you leave the suitcase at the hotel
Plugs and voltage: Costa Rica uses the same 110V and flat two-pin plugs as the United States and Canada. Travellers from the US and Canada need no adapter; visitors from Europe, the UK and Australia do.
Add these, by region
Monteverde & the cloud forest
A fleece or light insulated jacket. This is the item people regret not bringing more than any other
Long trousers — evenings get cool
A hat that won't blow off. Monteverde is genuinely windy
Shoes with grip: trails and hanging bridges are often wet
La Fortuna & Arenal
Swimwear you can wear twice a day — hot springs in the evening, waterfall in the morning
Flip-flops for the hot springs, plus proper shoes for trails
An umbrella. Locals use them constantly; it's more practical than a jacket in warm rain
A second pair of shoes, so you're never putting on wet ones
Guanacaste & the dry Pacific
More sun protection than you think — hat, sunglasses, long-sleeve rash guard. This is the hottest, driest, most exposed region
Electrolyte tablets or sachets if you're active in the heat
Light, loose clothing — and something smarter if you're staying at a resort
Caribbean & the humid south Pacific
Extra repellent. Wetter, greener, more insects
Anything that dries fast — humidity here is relentless and clothes don't dry overnight
A dry bag, if you didn't already pack one
What you can leave at home
Heavy hiking boots. Trail runners or light closed shoes are better in this heat and mud
A hairdryer. Nearly every hotel has one, and the humidity wins anyway
Lots of "nice" clothes. Costa Rica is informal almost everywhere — one smart outfit is plenty
Bulky beach towels. Hotels provide them; a quick-dry travel towel covers the rest
A big supply of toiletries. Supermarkets in every tourist town carry the usual brands
A word about luggage and vehicles
This is the part a driver notices that a packing list never mentions. Our vehicles are sized by passengers, but suitcases take space too. Five adults with five large suitcases and carry-ons don't fit the same way five adults with backpacks do.
So when you book, tell us how many bags and roughly what size — and mention surfboards, golf clubs, baby seats or bicycles. It costs nothing to say, and it's the difference between a comfortable drive and a puzzle at the kerb. Child seats are free on request.