The busiest tourist month in Costa Rica is consistently January, followed closely by late December and March (especially during Easter/Semana Santa). January falls in the heart of the "Dry Season," offering the most reliable sunny weather for beachgoers and hikers on the Pacific coast. During this "Peak Season," international arrivals surge as travelers from the Northern Hemisphere escape winter, leading to the highest hotel prices of the year and fully booked national parks like Manuel Antonio and Arenal. While the "Green Season" (May–November) is quieter and cheaper, the transition back to high-demand begins in mid-December. In 2026, the "swell" of tourism in January means that popular tours and car rentals often require booking at least 3 to 6 months in advance. For those looking to avoid the absolute peak while still enjoying good weather, mid-February or early May are often recommended as they offer a balance of manageable crowds and lower "shoulder season" pricing compared to the January rush.