Costa Rica remains under typical rainy season weather patterns this week, with the Intertropical Convergence Zone maintaining its position near the country and keeping humidity levels elevated.
While conditions start relatively moderate, rainfall is expected to intensify starting Thursday due to an upper-level trough moving into the region. This will promote greater atmospheric instability and create a wetter environment, especially across the Pacific and Central Valley.
Alert Status: The National Emergency Commission (CNE) has placed the Pacific, Central Valley, and Northern Zone under orange alert, while the Caribbean region remains on yellow alert. These elevated alert levels reflect ongoing concerns about saturated soil conditions from recent heavy rainfall.
The past week delivered substantial precipitation across Costa Rica, resulting in challenging conditions throughout the country:
Ground Saturation: Soil moisture levels have reached high saturation in many areas, meaning the ground has limited capacity to absorb additional rainfall. This increases vulnerability to landslides and flooding, particularly in areas that receive heavy rain later this week.
Infrastructure Impacts: Recent rainfall has caused localized flooding, landslides, and road damage across multiple regions. Numerous routes are experiencing closures or regulated passage due to washouts and slope failures.
Current Road Conditions (as of an update Sunday, October 5):
Complete Closures:
Regulated Passage (Open but Restricted):
The combination of saturated soils and continued rainfall this week, particularly from Thursday onward, warrants continued attention to weather conditions and official emergency management communications.
The most significant weather feature this week arrives Thursday as an upper-level trough moves into position over Central America. This meteorological pattern will enhance atmospheric instability and increase rainfall coverage and intensity, particularly affecting the Pacific slope and Central Valley.
Given already saturated ground conditions, areas that receive heavy rainfall Thursday and beyond face a higher risk for flooding and landslides.
Tropical Wave #36 is currently tracking over the Atlantic Ocean with potential to develop into a tropical cyclone between midweek and weekend. Forecast models indicate that if development occurs, the system’s track would keep it away from Central America without direct impacts to Costa Rica.
The Intertropical Convergence Zone remains positioned near Costa Rica throughout the week, maintaining the humidity and atmospheric instability characteristic of our October rainy season.
Partly cloudy skies are expected across the Pacific, Central Valley, and Northern Zone during morning hours. Rain is possible in Pacific regions and, to a lesser extent, in the Northern Caribbean. Morning conditions generally offer the best weather windows for outdoor activities requiring drier conditions.
Daily storm activity builds as the day progresses. The Central Valley and Pacific regions transition to mostly cloudy or overcast skies with rain, showers, and thunderstorms becoming common, especially from Thursday onward when the upper-level trough increases atmospheric instability.
The Caribbean and Northern Zone experience variable cloudiness ranging from partly to mostly cloudy, with rain and thunderstorms focused in mountain ranges and surrounding plains where orographic lifting enhances precipitation.
Pacific Region: Cloudy skies continue with rain, showers, and thunderstorms during early evening hours, particularly along coastal areas.
Caribbean and Northern Zone: Mountain areas remain prone to rainfall, especially during the more active period from Thursday through the weekend.
Central Valley: Partly to completely cloudy skies with variable rainfall and possible fog development, particularly during overnight and early morning hours.
Given current ground saturation and incoming weather patterns:
For emergencies, call 9-1-1
Temperature patterns remain within typical rainy season ranges despite persistent rainfall:
| Region | High °C (°F) | Low °C (°F) |
|---|---|---|
| Central Valley | 30° (86°) | 14° (57.2°) |
| North Pacific | 35° (95°) | 20° (68°) |
| Central Pacific | 32° (89.6°) | 14° (57.2°) |
| South Pacific | 33° (91.4°) | 16° (60.8°) |
| Caribbean | 31° (87.8°) | 16° (60.8°) |
| Northern Zone | 33° (91.4°) | 18° (64.4°) |
This forecast is based on the weekly outlook from Costa Rica’s National Meteorological Institute (IMN) and supporting meteorological data sources.
