The rainy season in Costa Rica, often referred to by locals as the "green season," typically runs from May through November, with the most intense rainfall occurring in October and November. During this period, the weather follows a predictable pattern: mornings are usually bright and sunny, followed by heavy tropical downpours in the mid-to-late afternoon and evening. This seasonality varies significantly by region; for instance, the North Pacific coast (Guanacaste) is the driest part of the country and may not see significant rain until June, while the Caribbean coast follows a different schedule entirely, often experiencing its driest months in September and October while the rest of the country is soaking. While the rain can make some unpaved rural roads muddy and difficult to navigate, the green season is highly favored by budget-conscious travelers because hotel rates are lower, the crowds are thinner, and the landscape is incredibly lush and vibrant. It is also the best time for white-water rafting as river levels rise, and for witnessing sea turtle nesting on both the Pacific and Caribbean shores.