Prepare for hot, humid summers. Shorts, T-shirts, sundresses, skirts and tank tops in lightweight fabrics should keep you cool. Take a sweater for evenings at a higher elevation.
Bring plenty of sunblock. Also include insect repellent, a wide-brimmed hat, sunglasses and a swimsuit.
Take rubber-soled sandals or hiking boots for journeys into the rain forests. Flip-flops and sandals are great for resorts and hanging out by the beach.
Pack separate clothes for evenings. Simple dresses are great for women, while men will do well in long shorts and a button-down shirt.
Prepare for cool winters, particularly in the northern regions and at higher elevations. Long pants and long-sleeved shirts are a must, while a fleece jacket or a sweater is advisable.
Take an umbrella if you plan to travel between May and November - Costa Rica's wettest period. A rain slicker will come in handy while hiking.
Take an electric converter and adapter.
