Women in Costa Rica dress more modestly than many women dress in the United States. Very short shorts are a fashion don't, as are skinny-strapped tank tops that allow bra straps to show. Natural fibers are more popular than polyester fabrics, and more appropriate when you are in steamy jungle conditions.
There are a myriad of ways women dress in Costa Rica. There is the traditional dress, typically worn in folkloric presentation or for holidays. For women, this may consist of a very full, tiered skirt in bright contrasting colors and a full white blouse with a crocheted, knit or embroidered collar, often with hand-done details. In daily life, however, the women of Costa Rica typically wear skirts that hit below the knee or long pants. Their shirts may be modest and dressy or just a casual T-shirt, but nothing risque.
Everyone in Costa Rica dresses in clothing appropriate for what can be lightning-quick changes in the weather. Women should always be prepared for a downpour with appropriate shoes, a water-resistant top layers such as a rain poncho. An umbrella and a change of dry socks and shoes will be your best friends.
While Costa Rican women may be relatively informal in their daily dress, this is not to be confused with being immodest or sloppy. The look many women aim for is European, with tailored cuts. Many travelers don the stereotypical tourist uniform of white sneakers, a fanny pack and a baggy sweatshirt, and they stand out.
Warm and humid conditions may prompt you to want to strip down to the minimum, especially at nighttime, but staying covered, albeit in loose, breezy clothing, is a woman's best resistance against being eaten alive by mosquitoes. A mosquito net and bug repellent can help, but long sleeves and long pant legs are best when you are off exploring in the Costa Rican jungle or settling into a hammock for a nap.