Costa Rica lies in the tropics, so temperatures are fairly constant all year round just varying with altitude. At sea level, a tropical 30-35°C is typical, tempered by sea breezes. The Central Valley and San José at around 3,800ft average a very pleasant 26°C. In the highlands temperatures can sometimes hover at around a chilly 10-13°C.
The dry season in Costa Rica runs between December and April - there are plenty of clear blue skies and sunshine, particularly in the Central Valley, the highlands and the beaches of the north and central Pacific coast (Tamarindo, Nicoya, Jacó and Quepos). This is the most popular season, with Christmas, Holy Week and Easter being particularly busy. Book well in advance at these times, as the best hotels can fill early.
The rainy or 'green' season in Costa Rica runs between May to November - mornings are typically clear, while afternoons grow cloudy and may bring rain - a short sharp burst or a couple of hours. Skies usually clear for a magnificent sunset before more rain at night. Travel is less popular, but the scenery is greener, prices can be lower, and there can be other bonuses, including wildlife events such as turtles coming to lay their eggs. September and October are the wettest months, when conditions can be tiresome, consequently we do not recommend travelling to Costa Rica at this time.