As Costa Rica transitions into early November, the country is experiencing a shift in weather patterns driven by moderate trade winds and upper-level atmospheric instability. These strengthening trade winds signal the gradual shift toward Costa Rica’s dry season, though November remains a transitional month with alternating periods of wetter and drier conditions.
This week’s weather story centers on Tuesday’s passage of Tropical Wave #43, which will enhance rainfall activity nationwide with the heaviest impacts concentrated in the Caribbean and Northern Zone regions.
Tropical Wave #43 will pass through Costa Rica on Tuesday, November 4th, bringing the week’s most significant rainfall event. The IMN reports that a configuration of high atmospheric pressure in the northern Caribbean Sea, combined with elevated humidity from the approaching tropical wave, will influence weather conditions particularly along the Caribbean coast.
Cloud cover begins increasing Monday night, with variable rainfall starting early Tuesday morning across the Caribbean and northeastern Northern Zone. These rains are forecast to increase in intensity throughout Tuesday morning and afternoon, with the possibility of heavy downpours. Rainfall totals over 12 to 24 hours are expected between 30 and 60mm (1.2 to 2.4 inches), with isolated maximums between 70 and 90mm (2.8 to 3.5 inches), particularly in eastern areas and the mountainous regions of the Caribbean coast.
The South Pacific will experience scattered showers with thunderstorms during Tuesday afternoon and along the coast in early evening. The Central Pacific sees rain in mountainous areas with coastal showers. Estimated rainfall amounts for these regions range between 10 and 40mm (0.4 to 1.6 inches), with maximums up to 70mm (2.8 inches) in the South Pacific over a 6-hour period.
Guanacaste could experience light rain and drizzle from mountainous areas to lowlands, with isolated showers on the Nicoya Peninsula.
The IMN warns that soil saturation remains high in the eastern watersheds of the Northern Zone and most of the Caribbean region. Extreme caution is advised in areas vulnerable to landslides and flash floods due to increased river flow in these watersheds. Tuesday’s tropical wave passage could trigger localized flooding or slope failures in already saturated areas.
Monday featured moderate trade winds working with upper-level atmospheric instability, generating cloudiness and intermittent rainfall over the Caribbean and Northern Zone. The country experienced partly to mostly cloudy skies with moderate winds in the Central Valley and Guanacaste. Caribbean and Northern Zone areas saw intermittent rain throughout the day, while Pacific regions experienced better weather with typical scattered (very scattered) afternoon thunderstorms. As evening approaches, partly to mostly cloudy conditions continue with possible drizzle in higher elevations and ongoing rain in the Caribbean and Northern Zone, setting the stage for Tuesday’s tropical wave arrival.
Tuesday Morning: Increasing cloud cover nationwide. Heavy rainfall developing in the Caribbean and northeastern Northern Zone, intensifying throughout the morning. Occasional drizzle possible in the Greater Metropolitan Area (GAM). Moderate winds continue in Central Valley and Guanacaste.
Tuesday Afternoon: Enhanced rainfall activity extends across the country. Pacific regions experience increased shower and thunderstorm activity. Caribbean and Northern Zone see continued heavy rainfall with possible downpours.
Tuesday Night: Active conditions persist with widespread rainfall across multiple regions, particularly Caribbean, Northern Zone, and Pacific coastal areas.
Trade winds persist at moderate intensity through midweek, then gradually decrease in the following days. Atmospheric humidity remains high throughout this week, maintaining rainfall potential across the country but we could have some beautiful days.
Mornings: Partly to mostly cloudy skies. Intermittent rain possible in Caribbean and Northern Zone during early part of this week, decreasing as days progress. Wind speeds moderate as trade wind influence diminishes.
Afternoons: North Pacific sees partly cloudy conditions with decreasing wind intensity as days progress. Central and South Pacific maintain partly to mostly cloudy skies with rain and thunderstorms, though less intense than Tuesday. Central Valley experiences partly cloudy conditions with scattered shower potential. Caribbean and Northern Zone show partly cloudy skies with mountain-focused rainfall.
Nights: Central Valley and North Pacific remain partly cloudy with possible drizzle in higher elevations, though wind gusts decrease compared to early in the week. Central and South Pacific see mostly cloudy conditions with possible rain and thunderstorms near coastal areas. Northern Zone and Caribbean range from partly to mostly cloudy with rain and thunderstorms, particularly during first days of this week.
Moderate trade winds characterized Monday and will continue into early in the week, with speeds between 30 and 65 km/h (19 to 40 mph). These winds affect Guanacaste mountainous areas and sporadically impact Central Valley mountains. Wind intensity gradually decreases as the week goes on.
Wind-Related Precautions:
The IMN recommends prevention measures for wind gusts and their potential damage to roofs, electrical wiring, signs, and trees, particularly in mountainous areas including national parks and volcanic regions. Air navigation should exercise caution due to increased turbulence. Maritime navigation faces increased rough seas, especially in the North Pacific and Gulf of Nicoya.
Additionally, the IMN strongly advises avoiding all types of burning, as fires can easily get out of control under current wind conditions.
Temperatures remain within typical early November ranges this week:
| Region | High °C (°F) | Low °C (°F) |
|---|---|---|
| Central Valley | 31° (87.8°) | 13° (55.4°) |
| North Pacific | 34° (93.2°) | 20° (68°) |
| Central Pacific | 32° (89.6°) | 15° (59°) |
| South Pacific | 33° (91.4°) | 15° (59°) |
| Caribbean | 32° (89.6°) | 20° (68°) |
| Northern Zone | 34° (93.2°) | 17° (62.6°) |
This forecast is based on outlooks from Costa Rica’s National Meteorological Institute (IMN).
