<human>:  What are the best times of the year for a vacation in Costa Rica?
<bot>: The best times of year for a vacation in Costa Rica are typically between late December and early April. The dry season falls between these months and is usually considered the best time for sightseeing and beach trips. The rainy season begins in May and normally lasts until November, though this can vary by region. It is still a great time to visit, however, if you are looking for a more adventurous experience, as many of the rivers will be running high and weather may be more conducive to outdoor activities.