What to wear in Costa Rica
 

I [male] will be in Costa Rica 12/15 - 12/27. Do I really need to buy any of the special clothing items advertised in many of the clothing travel catalogs, like "Travel Smith?" Or, can I take whatever is hanging in my close? Is "100% coton" bad and is nylon or poly too hot? I see picture of people wearing jeans, are they too hot? Any input would be appreciated.

You'll have to give some more info. Will you be staying at a resort or hiking the rain forests?

If you are staying in a town or at one of the resorts, normal lightweight summer clothes will be just fine.

Iriemon. Thank you for the quick response. I will be going on a tour with OAT. I realize most fodorites shun this kind of travel but I like it.
Our first day is in San Jose. Day 2, we visit Poas Volcano and will spend two days at Sarapiquis Centro Neotropico. We will raft the Rio Sarapiqui and visit the rainforest.
On 4 & 5 we stay at the Bosques de Chachagua Rainforest Hotel.
On day 6 we visit the Arenel Volcano National Park and stay at Montana del Fuego. Day 7, a boat ride on Rio Frio. Day 8 we go th Guanacaste Provience and stay at Buena Vista Lodge. Horseback riding and thermal baths are included, if you want. Day 10 we go to Punta Arenas Province and stay at Villa Lapas. aA tour of the Carara Biological Reserve and a cruise on Rio Tarcoles. Dat 11 drive to Punta Coral and cruise the Gulf of Nicoya then back to San Jose. I did not include all activities.
Any suggestions about clothing would be appreciated.

I don't think you need any special clothing in Costa Rica, although one item that I found useful were lightweight hiking pants that zip off so they can be converted into shorts (you can get them in any sporting store like EMS or REI or a catalog like LLBean).
Lightweight cotton t-shirts and shorts is what you will end up wearing most of the time. Take a couple of long sleeve shirts and long pants since the area around Arenal and Poas may be on the cool side. Long pants are also useful for horseback riding and when hiking in the jungle as a protection against insects. You will also need a rain jacket or a poncho.
A lot of Costa Ricans wear jeans and are comfortable. I thought they are generally fine in the Central Valley but too hot on the coast. The real problem with jeans is that if they get wet, you will never be able to get them to dry in Costa Rica.
As far as shoes, I found that a pair of light hiking boots or sneakers with good traction, a pair of teva type sandals and a pair of flip flops is all you need.
Have a great trip - it sound like a nice itinerary.

I have 2 pairs of zip off pants. Kind of pricey but double as two pairs of pants (long and short) They are lightweight and are good for any temp or weather because they dry quickly if wet. Also good for some rainforests because of the bugs. You can also wear them horseback riding. Jeans are not a good idea for CR. Chinos okay for the cooler areas like Arenal in the evening although it can be warm there also. Could use a pair for travel and the city. Some nylon is okay.
Costa Rica is a pretty casual place except for in the cities. You won't be spending much time in SJ so a couple of pairs of shorts, a bathing suit, and a pair of zip off pants would do you for the rest of your trip. I have a rain jacket with a hood that packs into a small bag that I hook to my belt loops so it is handy. Also doubles for me as a light jacket if it gets cool in areas like Arenal. A baseball cap worn under the hood works well to keep rain out of your face. There are also really cheap ponchos you can buy for a couple of bucks that you can tuck into your pocket in case of rain. Don't know how good they are.
Rio Sarapiqui area can be wet although not necessarily all the time but you should be prepared with quick drying clothes. It is a fascinating place and worth the discomfort.

Rio Sarapiqui area-warm and possibly wet
Arenal-upper 50's-80 degrees most likely. probably dry.

Poas-anything can happen. Cold, wet, dry, sun, warm.
Guanacaste area-hot and dry
Villa Lapas will be warm/hot(they do have a/c and a pool)and a bit humid. Good birding at the hotel if you are into birds. Saw a little pygmy owl in a tree across from bungalow 52 this year. They also have kinkajous there.
The Rio Frio by Cano Negro will be warm and most likely dry. Great birding btw.
Basically the list I gave you would be what I would pack for my 2-4weeks down there every year (plus some shirts of course and being a female I would pack one sun dress instead of chinos).
For shoes-New Balance all terrains are very popular for hiking and general use. When wet they dry quickly. I swear by mine and walk through streams all the time with them. A pair of teva type sandals also.

My husband and I just returned from Costa Rica. I'm not sure what special clothing items you'll need to pack since you'll be traveling to CR during the dry season. However, we found the following items to be absolute necessities during our trip (I'm including clothing and non-clothing items): "breathable" parkas, ponchos, umbrellas, flashlights (handy if you're going on a night hike), insect repellant, Aleve (unpaved roads make for sore backs and headaches), long pants (strongly suggested if you're going to explore any forest areas or travel to the cooler areas in the mountains. pants are also suggested if you're going to do a canopy tour which entails wearing a harness around your legs or if you're going horseback riding). 100% cotton wasn't too bad. It does take a bit longer to dry should you get wet but you shouldn't feel a need to run out a buy a bunch of nylon/poly clothing just for the trip. I wouldn't recommend jeans during the day but its cool in the mornings and sometimes in the evening. I'd also bring a calculator so you can easily convert your dollars into colones and vice versa. Good luck!

If you're active (hiking in rain forest, etc) I find that a few items specifically made for a tropical climate are VERY helpful to have in CR. The problem with only bringing clothes that aren't designed to dry quickly (100% cotton isn't) is when you try to rinse out a shirt or pants and hang them up to dry .... well, it's the tropics and humid and they take longer to dry. On my first trip to CR, I brought along 2 pairs of black jeans (a staple in my travel wardrobe); at the risk of being indelicate, I got very hot & sweaty wearing those jeans. I was on a trip thru Adventures Abroad and we moved around the country; therefore I didn't have enough time in one spot to have my clothes laundered @ hotel. Opted to leave one pair behind in a CR hotel as they were so smelly, I didn't want to put them in my suitcase. I learned from that initial trip and subsequently brought along 2 pairs of tropical pants (yes, I did buy from Travel Smith).

Thanks to everyone who replied. It looks like I already have everything I need. I'm really looking forward to this trip. Suzie2, I have to look up "kinkajous" Never heard of it.

Ranger60,

I know your post is years' old, but I wonder how you liked your OAT trip. We are considering the Real Affordable Costa Rica trip, but are worried about too much bus time. What did you think?

Megdean, This was my first trip with OAT and it was fantastic. I have since been to Peru,Egypt and this Oct. will be going to Thailand with OAT. Egypt was with Grand Circle, which is affiliated with OAT. To your question. I don't recall any of the bus trips being too long. We always stopped along the way for bird or wild life watching. If you go and are lucky enough to get the guide we had, Celice Reid, you will not be disapointed. She was fantastic. Her bio is on OAT's site. Celice carried her Sworski telescope with her all the tine and if she or our drive saw any birds or other wieldlife as we traveled, we would stop and Celice would get her scope out and set it up for those who wanted to view them. If you go and get her tell her Richard from Rochester NY said hello. Enjoy!

My husband and I took this OAT trip in February and would recommend it highly. We also had a very knowledgeable and enthusiastic guide who went out of his way to make sure everything was fine and that we saw a lot of wild life. The rain forest lodges were wonderful - no amenities like TV or phones, but Mother Nature in all her glory. I know you'll have a good time.

Thanks for the information on OAT. They are now at the top of my list. We travelled to Peru and Ecuador with them, and overall had a great time.