Costa Rica is a tropical country, you will probably have to deal with warm and humid weather conditions. Quick-drying and airy clothing is therefore ideal. Shorts, tank tops and slippers are the first types of clothes you think about, but if you go into the jungle for a hike or go out in the evening in places with mosquitoes, long pants and a long-sleeved shirt are nice to have. Special mosquito repellent pants are available if you want to further limit the chance of mosquito bites, but in my opinion not a necessity for the average tourist activities. If you don't want to over pack, a pair of zip-off pants are ideal. 

Since Costa Rica is a tropical country, it also receives a lot of rain. This varies per region and time of the year (read more at the seasons page), but nonetheless you want to be prepared. A raincoat, umbrella or poncho is therefore recommended. It stays warm in many places while it rains, so a thin breathable raincoat is ideal. You can always unzip when it gets too hot. For your day bag, make sure it is weatherproof or has a rain cover. Don't think too lightly about this, especially if you take an expensive camera with you in your bag. 

Last but not least, Costa Rica is a mountainous country. Places with higher altitudes like the central valley, Cartago, Turrialba, Orosi, Monteverde, can be a bit colder. Going high into the mountains like Volcano Poas, Volcano Irazu, Cerro de la Muerte, Cerro Chirripo, to name a few, it can be much colder. If you are going to visit these places, take a warm sweater that you can put on under a thin raincoat.

Bring sufficient swimwear. You will probably be visiting beautiful beaches and waterfalls. Are you going snorkeling, swimming, surfing, spend time on a boat, fishing, you name it, it might be wise to bring a UV50/UPF50 swim shirt or surf shirt. Costa Rica is close to the equator and the sun is very powerful. For that matter, bring a hat or a cap, sunglasses and sunscreen. Reef and sea life friendly sunscreen, please. A thin or quick dry (beach) towel is recommended and don’t forget a dry bag for your valuables, maybe one that you can put on or attach to your swimwear, so you don’t have to leave things like your phone and wallet unattended when you go for a swim. A dry bag is not only a necessity on the beach, but also when hiking in a humid rainforest. I also prefer some good water friendly shoes when walking the beach or through the sea. You will not be the first losing flip-flops due to currents or get stung in your feed by whatever tropical sea creature.  

The type of shoes also depend on your activities. If you are planning on hiking a lot on jungle trails, hiking shoes are to provide you with good grip and some safety against snake and insect bites (always wear closed shoes when hiking). My personal experience however is that sturdy hiking boots or shoes can get uncomfortably warm and heavy and do not dry quickly once they get wet. An often heard complained from travelers in humid conditions like the rainforest is that their shoes, once wet, stay wet for days. Safety first though, are you adventurous and planning on going off the beaten path, bring shoes that provide you with the safety levels you are comfortable with. 

Shoes I find comfortable for daily activities (which does not include the more adventurous hikes) are all-terrain sneakers or trail runners which are water-friendly, breathable and quick dry. This kind of shoes have both sneaker and water shoe abilities and are perfect for the beach, easy trails in national parks, hiking to waterfalls, rafting, etc. Note that activities like zip lining require closed toe shoes. 

A safety tip when it comes to shoes, every time before you put them on, shake them upside down to check for any creatures that might have crawled in, especially in remote areas. Never happened to me, but you don't want to put your feet in a shoe where a scorpion decided to take a nap.

Well, you will probably brush your teeth two times a day, so no need to remind you to bring your toothbrush. Things like toothpaste, shower gel, etc. are widely available in Costa Rica, but expect to pay more or less the same for these kinds of products as you are used to at home Toiletries and cosmetics are relatively expensive in Costa Rica. For the ladies, note that feminine hygiene products like tampons might be hard to find in certain areas. When it comes to make-up, do not over pack, because you will probably not use a lot due to hot and humid weather conditions. Don’t forget to bring some over the counter medication like painkillers (paracetamol aspirin, or ibuprofen), diarrhea medicine (Imodium or Pepto-Bismol), oral rehydration salts (ORS), mosquito or insect repellent, and motion sickness medicine if you are sensitive to motions caused by driving on windy roads or for wavy boat tours. Of course, this all depends on your personal preferences. Food safety and sanitation standards are high in Costa Rica, and these kinds of over the counter meds are widely available. Water is drinkable in most parts, but always check with locals or your hotel, because the condition of drinking water depends on weather conditions in certain areas. Bottled water is widely available, but note that in a lot of National Parks you are not allowed to bring single use plastics, pack a reusable water bottle. 

A first aid kit with (blister) plasters and disinfectant is always handy to have with you. Also bring a tick pen. In some areas, such as Corcovado, you may be bothered by ticks. You might also add an after bite extractor kit to your first aid carry on, although these kinds of kits are not very effective on deep tissue bites or stings. You can bring a mosquito net if you want, especially when you are planning on staying in budget locations along the coast. I have used a mosquito net once or twice during many travels in Costa Rica. Repellent, fans and air conditioning are also effective against mosquitos.

A safety tip when it comes to deep tissue bites or stings from for example snakes or scorpions. The first thing you or your fellow travelers want to do is to check what the hell bid you and make a photo. No, you don't have to be scared and cancel your trip!... these kinds of incidents are extremely rare, but if it does happen it will save precious time when treatment is needed a.s.a.p. and you are able to show or tell what bit or stung you.

Obviously you should not forget your passport, talking about passports, have you checked it isn't expired or going to expire soon? Make a photocopy of your passport and your driver’s license, in case you lose them. Make sure you are able to show your proof of return ticket (check the Travelling to Costa Rica page for details on Entry Requirements) and the address of your first stay in Costa Rica, as this information might be requested by the customs officer upon arrival. Do you use specific medication (not you're over the counter travel meds)? Check before you travel if it requires documentation to be allowed to enter through customs, and take the prescription with you in case you need to get it in Costa Rica for whatever unforeseen reason. 

Are you planning on using a credit card insurance policy for your rental car? Make sure you bring a letter of proof and details of the insurance conditions. Do you have travel insurance and health insurance? Make sure you have the (emergency) contact details with you, including contact details for your bank or credit card company. Always ask yourself the question if you have all this information available if your phone gets lost or stolen. Besides a hard copy, I usually keep important information on my Google Drive, so I have access from any device.