What To Bring

Costa Rica has a pretty constant range of temperatures because of its geographic location in the tropics. However, because of the presence of so many climate zones, it is suggested that you dress not only for hot, humid weather, but also for the cool breeziness of higher altitudes. The following is a list you might want to choose from:

A couple of bathing suits.
Shorts
T-shirts or tank tops
Loose-fitting cottons
Lightweight long sleeved shirt
Rubber sandals
Hats
Lightweight hiking boots with good tread
Athletic shoes for walks
Light sweater and/or jacket
Light cotton pants
Jeans (for horseback riding)
Extra socks
Sunglasses
Insect Repellent (75% DEET recommended)
Waterproof sun block lotion (SPF 29-40)
Towels
Folding sturdy umbrella
Rain jacket or poncho
Day pack
Cameras
Film for cameras (VERY expensive in Costa Rica)
Camera batteries
Binoculars
Flashlight
Medications
Plastic bags
Prepaid phone card to call home

A couple more bits of information:

The capital of San José is located at a higher elevation so it may be cool and breezy during the evening.

Dress in Costa Rica is typically casual, but traditionally, shorts are not worn to nice restaurants or parties.