San José, Costa Rica Weather: Your Year-Round Climate Guide

Known to locals as the land of "Eternal Spring," San José enjoys a temperate tropical highland climate. Nestled in the Central Valley at an elevation of approximately 3,800 feet (1,170 meters), the city is shielded from the extreme heat of the coastal lowlands, offering a unique blend of tropical lushness and refreshing mountain air.

Seasonal Rhythm: Verano vs. Invierno

In San José, the year is divided into two primary seasons based on rainfall rather than temperature changes.

• The Dry Season (Verano / Summer): December – April This period is characterized by clear blue skies and steady breezes. January and February are the windiest months, as the "Alisios" (northeast trade winds) sweep through the valley, often making the air feel crisp even under a bright sun. Rainfall is rare, and the landscape gradually transitions from lush green to a golden brown.
• The rainy Season (Invierno / Winter): May – November Locals also call this the "Green Season." The rain typically follows a predictable daily cycle: bright, sunny mornings followed by heavy, localized convectional showers or thunderstorms in the mid-to-late afternoon. By evening, the rain often clears, leaving the air cool and fresh. September and October are historically the wettest months.

Daily Climate Cycle

The weather in San José is remarkably consistent in its daily progression. A typical day begins around 60°F–65°F (15°C–18°C) at dawn. As the tropical sun rises, temperatures climb quickly, peaking between 77°F and 81°F (25°C–27°C) by midday. Because of the altitude, the heat rarely feels oppressive; the lack of stagnant air and lower humidity compared to the coast makes it feel like a mild summer day in more temperate latitudes. After sunset, the temperature drops efficiently, often requiring a light layer as it returns to the low 60s.

Local Phenomena and Microclimates

• Temporales: Occasionally, the city experiences a temporal—a weather event where low-pressure systems cause several consecutive days of constant, light-to-moderate rain and overcast skies. These are most common in October and often lack the lightning and thunder of typical afternoon storms.
• The Veranillo de San Juan: In late June or early July, there is often a brief, two-week "little summer" where the rains suddenly pause, providing a short window of dry, sunny weather in the middle of the rainy season.
• Microclimates: The Central Valley is a patchwork of microclimates. While downtown San José may be sunny, the surrounding escalations like Heredia or Cartago can be significantly cooler and foggier. A mere 20-minute drive up towards the Poás or Irazú volcanoes can see temperatures drop by 10–15 degrees.

How Locals Experience the Weather

Life in San José is built around the rain. In the wet season, social activities and errands are prioritized for the morning hours to beat the 2:00 PM downpours. The transition from dry to rainy season is celebrated for the way it "wakes up" the coffee plantations in the surrounding hills. Locals often refer to the light, misty rain that occurs at the edges of the valley as pelo de gato (cat's hair).

Because the sun is located nearly directly overhead year-round, its intensity is much higher than travelers from the north expect. Even on "cool" or cloudy days, the UV index remains high, and the weather "feels" warmer than the mercury suggests when you are standing in direct sunlight.