A mid-December arctic freeze over the U.S. and Canada pushed a high pressure system south and set up conditions to accentuate the seasonal shift in the inter-tropical convergence zone amplifying the trade winds across the 10th parallel…
…in other words…
The Rainy Season is Ending in Costa Rica!
The dry season in Costa Rica starts sometime between mid November and mid January. On average the middle of December.
This year November couldn’t end soon enough. It started out with heavy rains and severe flooding in the central and southern Pacific and ended with historic hurricane Otto making landfall on the Costa Rica Nicaragua border and crossing from the Caribbean to the Pacific wrecking havoc in the lowlands.
Otto was one of the latest forming hurricanes ever, the first ever hurricane to hit Costa Rica directly, and the first to ever to retain its Atlantic name as a Pacific storm after crossing the continent as a coherent system.
By mid December all that had passed and the Papagayo winds picked up. The arrival of dry season is not like flipping a switch and the rains will taper off not suddenly disappear. As always Guanacaste and the northwest will be drier sooner than the central Pacific and mountains. The Osa and far south Pacific never gets as dry as the north and the Caribbean side doesn’t really have a dry season.
Papagayo Winds Bring Dry Weather to Guanacaste
According to the Costa Rican Meteorological Institute the strong winds out of the northeast that began Dec 18 will continue across Guanacaste, the volcanic range, San José and the Central Valley blowing in the dry season weather patterns by Christmas. When the moist air from the Caribbean moves over land it is driven up cooling as it rises and expands. The moisture is squeezed out as rain on the eastern side of the continental divide leaving hot dry conditions to the west.
The winds typically pick up through January and continue into February frequently reaching 100 kph (60 mph). Even stronger gusts can uproot trees, damage buildings and are responsible for fatalities every year.