Squeezed between between seven and nine degrees north of the equator, Panama is located firmly within the tropics, with a climate to match: relentlessly hot and humid in the lowlands, cooling off fractionally to give balmy nights, whereas in the highlands, temperatures vary significantly with altitude, and can be chilly at night.
Most travellers visit during the shorter dry season (verano, “summer”), which runs from late December to the end of April, and with good reason. Azure skies predominate, at least on the drier Pacific plains, sheltered by Panama’s mountainous spine. The firmer going underfoot makes it easier to travel on unpaved roads and explore the rainforests, and the reduced rainwater run-off ensures clearer waters to swim in. The dry season also includes the lively holiday periods of Christmas, New Year, Carnaval and Holy Week, when flights and hotels in popular tourist spots are at a premium.
You’ll avoid the crowds and the mark-ups in the rainy season (invierno, “winter”), which stretches from May to December. Although the mountainous and rainforested regions in Panama are best avoided during the wettest months, since peaks are constantly swathed in cloud and tracks are boggy, if you stick to the lowland areas on the Pacific coast, the downpours, while frequent and intense, rarely last more than a few hours at a time, leaving plenty of sunny, dry periods to enjoy. In particular, the otherwise parched Azuero Peninsula offers much more picturesque scenery during its understated rainy season.
By contrast, the Caribbean coast receives almost twice as much rain as the Pacific, with virtually no recognizable dry season. Regional variations impact here too: the Trade Winds (at their strongest Dec to mid-Feb) make the water choppy and outer islands inaccessible in Bocas del Toro and Kuna Yala, while Bocas enjoys two relatively dry spells around March and October.